Direct proof of use
U.S. Army M109 self-propelled howitzers are directly documented in the 1990 Gulf War through deployment imagery and unit reporting. A National Archives image record shows M-109 self-propelled howitzers of the 24th Infantry Division loaded onto rapid-response vehicle cargo ships at Savannah for deployment to Saudi Arabia during Operation Desert Shield.
DVIDS also records 1/201st Field Artillery, West Virginia Army National Guard, loading assigned M109 howitzers for overseas movement, arriving in Saudi Arabia on February 2, 1991, staging as part of the ground force, firing preparatory rounds into Iraq on February 17, and firing 447 high-explosive rounds during the campaign.
Sources: 24th Infantry Division M109s Deploy for Desert Shield, A West Virginian's Memories of Desert Storm
Timeline
On January 23, 1991, the National Archives image metadata placed 24th Infantry Division M109 howitzers at Savannah, Georgia, before shipment to Saudi Arabia for Operation Desert Shield. The record documents deployment preparation rather than a firing event, but it directly ties M109 vehicles to the coalition buildup for the Gulf War.
On February 2, 1991, the 1/201st Field Artillery reached Dhahran, Saudi Arabia, after loading its assigned M109 howitzers for overseas movement. DVIDS then places the battalion near Rafha as part of the ground force and records preparatory firing into Iraq on February 17, one week before the ground offensive began.
Sources: 24th Infantry Division M109s Deploy for Desert Shield, A West Virginian's Memories of Desert Storm
Operational role
The documented role was coalition 155 mm self-propelled artillery support for armored and ground maneuver forces. The 24th Infantry Division image shows M109s being shipped with a mechanized division during Desert Shield, while the 1/201st account describes M109-equipped artillery moving with the western ground-force maneuver and firing preparatory missions before the ground war.
The direct sources support U.S. Army use and deployment. They do not establish Iraqi M109 use in the conflict, and the strongest firing detail in the cited record comes from the 1/201st Field Artillery account rather than a comprehensive theater-wide artillery expenditure summary.
Sources: 24th Infantry Division M109s Deploy for Desert Shield, A West Virginian's Memories of Desert Storm