The "cotton gin' is BEST described as a es )

A cotton gin  meaning "cotton engine" is a machine that quickly and easily separates cotton fibers from their seeds, enabling much greater productivity than manual cotton separation

Explanation:

united states reinforcements contributed greatly to three allied victories in france at: cantigny (first major american battle), argonne (the largest in the united states military history, involving 1.2 million american soldiers), and château-thierry (one of the first actions under general pershing).