The first sustained American offensive of the war, although a minor action in itself, the Battle of Cantigny was fought on 28 May 1918, the second day of the great German offensive comprising the Third Battle of the Aisne.

A regiment of the American 1st Division (some 4,000 troops), under Major-General Robert Lee Bullard, captured the village of Cantigny, held by the German Eighteenth Army commanded by von Hutier and the site of a German advance observation point, strongly fortified.

Aiding the attack, the French provided both air cover in addition to 368 heavy guns and trench mortars, plus flamethrower teams. The advancing American infantry were preceded into the village by twelve French tanks following a two-hour advance artillery barrage.

In taking the village the Americans expanded their front by approximately a mile. A minor success, its significance was entirely overshadowed by the battle underway along the Aisne, some fifty miles to the north-west.

In the face of seven fierce counter-attacks that day and the next the U.S. forces held their position with the loss of 1,067 casualties; they captured around 100 German prisoners. The American success at Cantigny was followed by attacks at Chateau-Thierry and Belleau Wood in the first half of June.