No Americans fought on the Kokoda track but 24,000 participated in the Battle of Buna-Gona, at Milne Bay, or were involved in air and coastal operations...
The major American formation present was the 32nd Division composed of National Guards, a militia force from the states of Michigan and Wisconsin. This division arrived in Australia in May 1942 and went into battle at Buna in November 1942. A regiment of 41st Division was engaged at Sanananda and United States Army engineers fought at Milne Bay and maintained communications and supply at Port Moresby. American anti-aircraft units also served at Port Moresby, Milne Bay and Buna.