SD:Mortar 107mm

 is a United States Artillery unit.

Overview
M2 4.2 inch Mortar was developed from the Stokes mortar similar to British Counterpart 4.2-in Mortar. M2 4.2 inch Mortar were ostensibly fires smoke shells but chemical, Gas and HE shells were created. Chemical and Gas weapons were on stand by to be used in retaliation should the enemy employ chemical weapons. But US forces found the HE and white phosphorus rounds to be useful. These Mortar were used in Chemical Mortar Battalions that were attached to infantry divisions.

1st Infantry had companies of 81st Chemical Mortar Battalion in support. 2nd Infantry had other companies of 81st Chemical Mortar Battalion during the Normandy Campaign.