Mortars are the infantry commander’s “hip pocket” artillery. Light infantry companies have a pair of 60mm mortars assigned, to provide quick suppressive fires and smoke.
The M224 60mm mortar has been in service since the early 1980’s, replacing the older, heavier and shorter range M2 60mm mortar of WWII vintage. It is in service with both the Army and the Marines, as well as several allied nations.
Here’s a video of the mortar squad of Company K, 3rd Battalion, 5th Marines firing a mission with their mortar during the Battle of Fallujah. Notice how close to the action they are. The max range of the 60mm mortar is just over two miles. Also, notice that all five rounds are fired before the first round impacts.
Other mortars in use with the US include 81mm mortars (at battalion level in light companies) and the 120mm mortar, used in mechanized, Stryker, and armored battalions.