In the immediate aftermath of the Japanese attack on Pearl Harbor, Marine Sgt. John Basilone prepares to ship out and confront the enemy somewhere in the Pacific, while budding journalist Robert Leckie enlists in the Marine Corps. Eugene Sledge, unable to enlist because of a heart murmur, says farewell to his best friend, Sidney Phillips, who is about to leave for boot camp. Exactly eight months after Pearl Harbor, the 1st Marine Division, including Leckie and Phillips, lands on Guadalcanal in order to secure its strategically vital airfield and prepare for the inevitable counterattack.

Basilone and the 7th Marines arrive on Guadalcanal to reinforce Leckie and the rest of the 1st Marine Division as they continue to defend the crucial airstrip. Basilone plays a key role in repelling a nighttime Japanese attack, but suffers a frightful personal loss. After four months of continuous action, the exhausted and disease-ridden members of the 1st Marine Division are evacuated off the island.

Physically and mentally debilitated after the four-month ordeal on Guadalcanal, Leckie, Basilone and thousands of their comrades land in Melbourne, where they are greeted by adoring crowds and viewed as the saviors of Australia. While his buddies carouse, Leckie becomes deeply attached to an Australian woman and her first-generation Greek family. Meanwhile, Basilone is awarded the Medal of Honor and is asked to return home to help sell U.S. war bonds.

Finally enlisted as a Marine, Sledge trains for combat at Camp Elliott. The 1st Marine Division lands at Cape Gloucester on the Japanese-held island of New Britain. As Leckie and the other Marines battle the Japanese, they quickly realize that the more ominous enemy is the smothering jungle itself. Having survived Gloucester and stationed on the godforsaken island of Pavuvu, Leckie begins displaying the physical and mental effects of combat and is sent to a naval hospital on nearby Banika for psychiatric observation.

Basilone’s celebrity grows as he travels across the country on the war bonds tour. On Pavuvu, Sledge, assigned to the 5th Marines, 1st Marine Division, is briefly reunited with Phillips and Leckie rejoins his company. Sledge then gets his first taste of combat as he, Leckie, and the rest of the 1st Marine Division meet fierce Japanese resistance while landing on the intricately and heavily defended coral island of Peleliu.

Despite the suffocating 115-degree heat and a lack of clean drinking water, Sledge, Leckie and the other Marines confront the highly-fortified enemy as they attempt to capture the Peleliu airfield. After seeing his comrades badly injured, Leckie himself is wounded and evacuated from the island. Sledge witnesses the shocking truth about what is sometimes required to survive and fight another day.

The Marines, including the newly christened “Sledgehammer,” continue the battle of Peleliu against an enemy determined to fight to the last man. Devastated by the loss of a revered leader, and witnessing unimaginable barbarity on both sides, Sledge veers to the very edge of moral collapse. Their objective finally secured, the Marines return to Pavuvu fundamentally changed by their experience on Peleliu.

Increasingly frustrated by his role campaigning for war bonds, Basilone convinces the Marines to allow him to train troops headed for combat. Transferred to Camp Pendleton, he enjoys a whirlwind romance with an initially reluctant female Marine, Lena Riggi. But the couple know they are living on borrowed time, as Basilone is soon to take part in the Marine landing on Iwo Jima.

After battling across the island of Okinawa for more than a month, Sledge and the rest of the 1st Marine Division are ordered to relieve an Army division that has been in combat against the most strongly defended Japanese position on the island. The primordial conditions and the moral dilemma posed by the presence of civilians put tremendous strain on the physical and psychological endurance of Sledge and the other Marines.

After the Japanese surrender, Leckie, healed from his wounds, leaves the hospital and returns home, while Sledge heads back to Alabama to be reunited with his family and Sid Phillips. Lena visits Basilone’s home and has an emotional meeting with his family. Leckie adjusts to post-war life by resuming his old job and starting a new relationship, but for Sledge, unsure why he survived the war seemingly unscathed, adjustment will require more time.

Easy Company is introduced to Captain Sobel, who has the group undergo hard and unfair training. As a result, Sobel comes into conflict with his men, including Richard Winters, his executive officer. The company is shipped to England to prepare for D-Day. After displaying a lack of leadership ability in the field, Sobel is reassigned.

Easy Company lands in Normandy, scattered all across and away from their drop zone. 1st Lt. Meehan, commander of Easy, is killed when his plane suffers a direct hit and 1st Lt. Winters must take command. With a small group of men, Winters takes out a set of guns at Brécourt and thereby wins the respect of his fellow soldiers as a leader. 1st Lt. Speirs is introduced, around whom rumours start to circulate after he is believed to have massacred a group of German prisoners of war.

Easy Company are sent to liberate the French village of Carentan, where they lose several men in heavy fighting. The episode focuses on Private Albert Blithe, who struggles with crippling anxiety following the battle. After he is finally spurred into action by Winters during a German counterattack, Blithe overcomes his fears but days later gets shot in the neck by a German sniper after volunteering to be lead scout in a patrol.

New characters are introduced when replacements join Easy Company, who struggle to be accepted by the veterans who fought at Normandy. The Company is sent to parachute into and fight in the Netherlands as part of Operation Market Garden, where they liberate Eindhoven. During combat in Nuenen, the replacements integrate themselves with the Company, but the Company is forced to retreat. The episode follows Sergeant Denver "Bull" Randleman, the replacements' immediate superior, as he evades German soldiers in Nuenen after being cut off and forced to stay there and must wait until the enemy leaves in the morning.

Winters writes a report on the challenge of an unexpected resistance to a German attack, and is haunted by his conscience after shooting a teenage German soldier; this flashback occurs several times in later episodes. Operation Pegasus is depicted. Easy Company is called to Bastogne to repel the sudden German counterattack.

Easy Company experiences the Battle of the Bulge and have to hold ground near Bastogne while running low on ammunition and other supplies. The episode focuses on medic Eugene "Doc" Roe as he helps out his fellow soldiers where he can, while also scrounging for medical supplies, of which the Company is dangerously low. He also befriends a Belgian nurse in Bastogne, who is later killed during a German bombing raid.

Easy Company battles near Foy, Belgium, losing numerous men. In the episode, the actions of 1st Lt. Norman Dike, the Company's commander, are examined and questioned. He is eventually relieved by 1st Lt. Ronald Speirs, who becomes the Company's new leader. Serving as narrator is 1st Sgt. Carwood Lipton, who attempts to keep the morale of the men up as they endure their trials in the forest near Foy, earning him a pending field promotion to 2nd. Lt. for his leadership ability.

Easy Company carries out a dangerous mission in Haguenau as David Webster (who narrates this episode) returns from a hospital. Together with new replacement 2nd Lt. Jones, he eventually (re)integrates with the other soldiers, whose experiences at Bastogne have made them weary and closed off from Webster due to the fact he didn't try and leave hospital early unlike other soldiers in the company. At the end of the episode, Captain Winters is promoted to Major, and Lipton is promoted to 2nd Lt.

As Nixon battles alcoholism, Easy Company enters Germany. A concentration camp near Landsberg is discovered by a patrol. This site leaves many soldiers both shocked and disgusted at what they're witnessing at the hands of the Nazi Germans. The episode was based on the liberation of Kaufering IV in the area of Hurlach.

Easy Company enters the Bavarian town of Berchtesgaden, once home to Hitler's top officers. They find the town deserted and rush on to capture Hitler's famed "Eagle's Nest" before the French can get there. Here they learn of the German army's surrender. Amid the celebrations, Winters brings his friend Cpt. Nixon to Herman Goring's house, where he presents a "gift" of Goring's impressive liquor collection. The company moves on to Austria, where they learn that those without enough "points", awarded for combat experience, will be sent to fight in the Pacific. Despite all that they've been through, few of the men are eligible to go home. Winters and Nixon request an immediate transfer to a unit that is going to the Pacific, but they are denied. Winters continues to work to keep the men of his company out of harm's way. Meanwhile, the troops are restless. Liebgott takes Webster to the home of a man he believes was a labor camp Commandant. Despite Webster's concern about Liebgott's lack of proof, when the man tries to escape, he is killed. As the occupation of Zell Am See, Austria continues, one member of the company is killed in a car accident and another is shot in the head by a drunken soldier from another Company. As Winters explains in his narration, "They didn't have the points. What they did have were weapons, alcohol, and too much time on their hands". Thus, even after the official fighting was over, tragedies still occurred and some brave souls only made it home in a pine box. That said, the series ends with the happy news that the Japanese have surrendered, and the surviving men of Easy Company can return home.

In the immediate aftermath of the Japanese attack on Pearl Harbor, Marine Sgt. John Basilone prepares to ship out and confront the enemy somewhere in the Pacific, while budding journalist Robert Leckie enlists in the Marine Corps. Eugene Sledge, unable to enlist because of a heart murmur, says farewell to his best friend, Sidney Phillips, who is about to leave for boot camp. Exactly eight months after Pearl Harbor, the 1st Marine Division, including Leckie and Phillips, lands on Guadalcanal in order to secure its strategically vital airfield and prepare for the inevitable counterattack.

Basilone and the 7th Marines arrive on Guadalcanal to reinforce Leckie and the rest of the 1st Marine Division as they continue to defend the crucial airstrip. Basilone plays a key role in repelling a nighttime Japanese attack, but suffers a frightful personal loss. After four months of continuous action, the exhausted and disease-ridden members of the 1st Marine Division are evacuated off the island.

Physically and mentally debilitated after the four-month ordeal on Guadalcanal, Leckie, Basilone and thousands of their comrades land in Melbourne, where they are greeted by adoring crowds and viewed as the saviors of Australia. While his buddies carouse, Leckie becomes deeply attached to an Australian woman and her first-generation Greek family. Meanwhile, Basilone is awarded the Medal of Honor and is asked to return home to help sell U.S. war bonds.

Finally enlisted as a Marine, Sledge trains for combat at Camp Elliott. The 1st Marine Division lands at Cape Gloucester on the Japanese-held island of New Britain. As Leckie and the other Marines battle the Japanese, they quickly realize that the more ominous enemy is the smothering jungle itself. Having survived Gloucester and stationed on the godforsaken island of Pavuvu, Leckie begins displaying the physical and mental effects of combat and is sent to a naval hospital on nearby Banika for psychiatric observation.

Basilone’s celebrity grows as he travels across the country on the war bonds tour. On Pavuvu, Sledge, assigned to the 5th Marines, 1st Marine Division, is briefly reunited with Phillips and Leckie rejoins his company. Sledge then gets his first taste of combat as he, Leckie, and the rest of the 1st Marine Division meet fierce Japanese resistance while landing on the intricately and heavily defended coral island of Peleliu.

Despite the suffocating 115-degree heat and a lack of clean drinking water, Sledge, Leckie and the other Marines confront the highly-fortified enemy as they attempt to capture the Peleliu airfield. After seeing his comrades badly injured, Leckie himself is wounded and evacuated from the island. Sledge witnesses the shocking truth about what is sometimes required to survive and fight another day.

The Marines, including the newly christened “Sledgehammer,” continue the battle of Peleliu against an enemy determined to fight to the last man. Devastated by the loss of a revered leader, and witnessing unimaginable barbarity on both sides, Sledge veers to the very edge of moral collapse. Their objective finally secured, the Marines return to Pavuvu fundamentally changed by their experience on Peleliu.

Increasingly frustrated by his role campaigning for war bonds, Basilone convinces the Marines to allow him to train troops headed for combat. Transferred to Camp Pendleton, he enjoys a whirlwind romance with an initially reluctant female Marine, Lena Riggi. But the couple know they are living on borrowed time, as Basilone is soon to take part in the Marine landing on Iwo Jima.

After battling across the island of Okinawa for more than a month, Sledge and the rest of the 1st Marine Division are ordered to relieve an Army division that has been in combat against the most strongly defended Japanese position on the island. The primordial conditions and the moral dilemma posed by the presence of civilians put tremendous strain on the physical and psychological endurance of Sledge and the other Marines.

After the Japanese surrender, Leckie, healed from his wounds, leaves the hospital and returns home, while Sledge heads back to Alabama to be reunited with his family and Sid Phillips. Lena visits Basilone’s home and has an emotional meeting with his family. Leckie adjusts to post-war life by resuming his old job and starting a new relationship, but for Sledge, unsure why he survived the war seemingly unscathed, adjustment will require more time.