Racism emerged as an ideology after slavery began in the united states sometime in the sixteenth and seventeenth centuries during the sectional rivalry in the early nineteenth century only in the twentieth century

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).