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The Guadalcanal Campaign, 1942 to 1943: the Pacific turns

Second World War, Pacific · August 1942 to February 1943 · Allies vs Japan · ~6 min read · Updated October 2026

By Echoes of Battle

United States Marines resting in the field on Guadalcanal, 1942

At a glance

Allies (United States, with Australia)Maj. Gen. Alexander Vandegrift; Adm. William Halsey
vs
Empire of JapanJapanese Army and Navy commanders
Date
7 August 1942 to 9 February 1943
Location
Guadalcanal, Solomon Islands
Period
Second World War, Pacific theatre
Outcome
Decisive Allied victory
By the numbers
SideStrengthLosses
AlliesTens of thousands over the campaign~7,000 killed (land, sea and air)
JapanTens of thousands~20,000 to 31,000 killed (estimates vary)

Figures cover the whole campaign and are approximate.

Quick answer

The Guadalcanal campaign, fought from 7 August 1942 to 9 February 19431, was the first major Allied offensive of the Pacific War2. American forces, chiefly the Marines, landed to seize a Japanese airfield and then held it through six months of brutal land, sea and air battles until Japan abandoned the island. The victory ended Japan's advance and passed the strategic initiative to the Allies.

In August 1942 the United States took the offensive in the Pacific for the first time, landing Marines on a jungle island few had heard of: Guadalcanal. The six-month battle that followed, on land, at sea and in the air, broke the momentum of Japan's war.

Part of The greatest battles of the Pacific War · Before: The Battle of Midway · Next: The Battle of Tarawa · Key figures: John Basilone, Chesty Puller

The first Allied offensive

After stopping Japan at the Coral Sea and Midway, the Allies went over to the attack. On 7 August 1942 US Marines landed on Guadalcanal and nearby islands and seized a half-built Japanese airfield, which they named3 Henderson Field. Holding that airfield became the key to the whole campaign.

Aerial photograph of a jungle airstrip near the coast of Guadalcanal
Henderson Field from the air in late August 1942, photographed from an aircraft of the carrier USS Saratoga. Public domain

Holding Henderson Field

The Japanese poured in troops to retake the field, and the Marines fought off repeated assaults through the jungle, including desperate night battles along the ridges4 and the Matanikau River. The aircraft flying from Henderson Field, the Cactus Air Force, gave the Allies control of the skies5 by day.

Four maps of Guadalcanal showing the landings and the battles around the airfield
The Guadalcanal campaign of 1942: the initial landings, the attack on Bloody Ridge in September and the Japanese counteroffensive of October around Henderson Field, from the US Military Academy atlas. Public domain

The battles at sea

Around the island the two navies fought a series of ferocious night actions in the waters soon nicknamed Ironbottom Sound for the ships sunk there4. Both sides lost heavily, including carriers and cruisers, as each tried to land reinforcements and cut off the other.

Photograph of an aircraft carrier pouring thick smoke at sea
The carrier USS Wasp burning after being torpedoed by a Japanese submarine on 15 September 1942 while escorting reinforcements to Guadalcanal. Public domain
One jungle airfield decided the first six months of America's Pacific war.

Attrition and withdrawal

Unable to feed and supply its troops against Allied air and sea power, Japan lost thousands to combat, disease and starvation5. In early February 1943 the Japanese quietly evacuated3 their surviving soldiers, and the campaign ended in Allied victory.

Aerial photograph of burning ships run aground on a beach with a dive bomber in the foreground
A US Navy Dauntless dive bomber flies past Japanese transports beached and burning on Guadalcanal, 16 November 1942, after a failed attempt to land reinforcements. Public domain

Why Guadalcanal mattered

Guadalcanal was one of the first major land defeats of the Japanese army in the war and the point at which the Pacific turned: from here the Allies advanced and Japan was on the defensive. It was a campaign of attrition that Japan could not afford. See also the Battle of Midway and the Battle of Okinawa.

Frequently asked questions

When was the Guadalcanal campaign?

It ran from the landings on 7 August 1942 to the Japanese evacuation on 9 February 1943.

Who won at Guadalcanal?

The Allies, chiefly the United States. Japan abandoned the island after failing to retake its airfield.

Why was Guadalcanal important?

It was the first major Allied offensive of the Pacific War and one of the first major defeats of the Japanese army, shifting the initiative to the Allies.

What was Henderson Field?

The airfield the Marines captured and held; the aircraft based there gave the Allies daytime control of the sea and skies around the island.

Why was it so costly?

It was a long campaign of attrition on land, at sea and in the air; Japanese losses to combat, disease and starvation ran into the tens of thousands.

Sources and notes

Numbered notes in the text point to the works below.

  1. Wikipedia, “Guadalcanal campaign” ↩
  2. John Miller Jr., Guadalcanal: The First Offensive (United States Army in World War II: The War in the Pacific) (Historical Division, Department of the Army, 1949). ↩
  3. The National WWII Museum, “The Solomon Islands Campaign: Guadalcanal” ↩ a b
  4. The National WWII Museum, “War on a Shoestring: The Fight for Guadalcanal” ↩ a b
  5. Richard B. Frank, Guadalcanal: The Definitive Account of the Landmark Battle (Random House, 1990). ↩ a b

Hold Henderson Field

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