Short answers, pulled from the story.
The Battle of Buna-Gona was fought from the 16th of November 1942 to the 22nd of January 1943. It followed the Kokoda Track campaign and formed part of the New Guinea campaign in the Pacific theatre of World War II.
Australian and United States forces fought Japanese troops dug in at three beachheads on the north coast of New Guinea: Buna, Sanananda and Gona. The main Allied units were the Australian 7th Division and the US 32nd Infantry Division, later reinforced by additional brigades and regiments.
The battle was fought along a 25 km stretch of New Guinea's north coast at Buna, Sanananda-Giruwa and Gona, roughly 160 km northeast of Port Moresby. The terrain was low-lying coastal swamp bordered by mangroves, kunai grass and neglected coconut plantations.
MacArthur repeatedly pressured his commanders for a rapid conclusion, driven more by a need to secure his own command politically than by strategic necessity. He never visited the front, underestimated Japanese defences after his chief of staff called them "hasty field entrenchments," and his pressure lengthened the battle and increased Allied casualties.
Most of the Japanese garrison at Buna-Gona was evacuated by sea or escaped overland toward Salamaua and Lae, with between 1,000 and 1,900 men getting out on foot. The defenders left behind fought to the death almost to the last man, and there was widespread evidence the starving garrison had resorted to cannibalising the dead.
Allied losses came at a higher rate than those suffered earlier at Guadalcanal, worsened by shortages of food, ammunition and suitable equipment, and by malaria, which hospitalised far more men than combat wounds did. The battle exposed serious problems with US 32nd Division combat effectiveness and forced the Allies to learn costly lessons about jungle warfare.