[1] In 1943, General Mark Clark's Fifth Army established a policy that no infantry division would be committed to combat without a chemical mortar battalion attached.
On the first day that General George S. Patton's Third Army became operational, in the summer of 1944, he issued a standing order to his staff that no infantry division would be committed to combat without a chemical mortar battalion attached, and no infantry regiment would be committed without a mortar company attached.
[2] Mortars came to be acknowledged by U.S. Army commanders and personnel as being one of the most effective means of quickly striking at stationary targets, such as machine gun nests, prepared strongpoints, pillboxes and even artillery positions.
Other advantages mortars offered compared to full-sized artillery pieces were their easier transportation, assembly, and disassembly.
Thanks to their relatively small size, mortars were able to fire from concealed positions, such as natural escarpments on hillsides, or from woods.
The Stokes mortar could fire twenty shells per minute and had a range of 1,100 yards (1,000 m) and in this way was capable of overwhelming enemy trenches.
By the 1930s, after modifying the bore, improving the two-legged support and the recoil mechanism, and producing barrels made of seamless nickel steel, the M1A1 model was capable of sending shells 2,400 yards (2,200 m) Chemical mortars were so named because of their original intent of firing poison gas, incendiary and smoke marker shells.
The propellant charges were manufactured as square disks with a hole in the middle, strung together, fitted into cartridges, and sewn together into bundles of various thicknesses.
The rifled barrel gave the mortar remarkable accuracy; fire was often called on targets within fifty yards of friendly positions.
The mortar was called the "grass-cutter" by German troops because its high explosive shell exploded and fragmented just a few inches above ground level.
The mortars often fired white phosphorus munitions (WP) shells to block enemy observation with smoke; white phosphorus also caused casualties and fires, being especially effective against dug-in troops because the burning particles arced upward and fell directly down into foxholes.
It was inactivated on 15 April 1935 and concurrently reorganized entirely with Organized Reserve personnel as a Regular Army Inactive unit.
The 2nd Chemical Regiment was constituted in the Regular Army 1 April 1931, assigned to the Zone of the Interior, and allotted to the Fourth Corps Area.
In February 1944, a disappointed Rowan learned that the battalions in the United States had already been reorganized under the September 1943 table of organization.
[20] In July 1944, the 84th Chemical Mortar Battalion in Italy reorganized under the "long ignored" table of organization of September 1943.
In mid-1944, the War Department again revised the table of organization based upon the recommendations of Chemical Warfare Service officers with combat experience.
[21] Per Table of Organization and Equipment 3-25 of 29 September 1944, a typical chemical mortar battalion had an establishment of 37 officers, 138 NCOs and 481 junior enlisted men not counting the attached medical detachment.