World War II: The 503rd Parachute Infantry Regiment lands and occupies Lae Nadzab Airport, near Lae in the Salamaua-Lae campaign.

The SalamauaLae campaign was a series of actions in the New Guinea campaign of World War II. Australian and United States forces sought to capture two major Japanese bases, one in the town of Lae, and another one at Salamaua. The campaign to take the Salamaua and Lae area began after the successful defence of Wau in late January, which was followed up by an Australian advance towards Mubo as the Japanese troops that had attacked Wau withdrew to positions around Mubo. A series of actions followed over the course of several months as the Australian 3rd Division advanced north-east towards Salamaua. After an amphibious landing at Nassau Bay, the Australians were reinforced by a US regimental combat team, which subsequently advanced north up the coast.

As the Allies kept up the pressure on the Japanese around Salamaua, in early September they launched an airborne assault on Nadzab, and a seaborne landing near Lae, subsequently taking the town with simultaneous drives from the east and north-west. As the situation around Lae grew more desperate, the Salamaua garrison withdrew, and it was captured on 11 September 1943, while Lae fell shortly afterwards on 16 September, bringing the campaign to an end.

The 503rd Infantry Regiment, formerly the 503rd Parachute Infantry Regiment (503rd PIR) and the 503rd Airborne Infantry Regiment (503rd AIR), is an airborne infantry regiment of the United States Army. The regiment served as an independent regiment in the Pacific War during World War II; at Fort Campbell, Kentucky; in Okinawa, Japan; and in Germany. Regimental elements have been assigned to the 2nd Infantry Division, the 11th Airborne Division, the 24th Infantry Division, 25th Infantry Division, the 82nd Airborne Division, 101st Airborne Division, and the 173rd Airborne Brigade Combat Team. Regimental elements have participated in campaigns in the Vietnam War, Operation Enduring Freedom–Afghanistan, and Operation Iraqi Freedom. The regiment claims 15 Medal of Honor recipients: two from World War II, ten from Vietnam, and three from Afghanistan. A parent regiment under the U.S. Army Regimental System. The regiment's 1st and 2nd Battalions are active, assigned to the 173rd Airborne Brigade, based at Caserma Ederle, Vicenza, Italy. The 3rd and 4th Battalions as well as Companies E, F, G, H, and I have been inactived.