Mortars are the oldest and
most widely used artillery,
and were a critical element of trench warfare during World War I.
In the 1930s, the U.S. Army Ordnance Department ordered the design of a 60mm mortar, after purchasing the design license for the Mle1935. This new weapon would be known as the M2, and soon became the most popular weapon of its type.
The standard U.S. mortar battalion was equipped with the 81mm mortar, also created under a license from Bran. The M6A1 Hand Cart was developed for transporting these weapons, along with a special harness so they could be moved by mules. However, the M21 half-track remained the mortar carrier of choice. From July 1940 to June 1945, the U.S. Army issued a total of 110,000 mortars.