During the interwar period, the regiment's 1st Battalion experienced periods of inactivation and relocation, operating out of Fort Des Moines, Iowa, and Fort Riley, Kansas, before arriving at Fort Lewis, Washington, in 1930. In 1933, the regiment was assigned to the 3rd Infantry Division, establishing a relationship that would define much of its combat legacy. In October 1940, as the U.S. Army restructured into "triangular" divisions to streamline combat efficiency, the regiment reorganized as the 9th Field Artillery Battalion.  The battalion entered World War II in November 1942, landing in North Africa during Operation Torch. Serving as the 3rd Infantry Division's 155mm general support unit, the battalion fought across North Africa, participated in the amphibious assaults of Sicily and Anzio, and pushed through Southern France, the Rhineland, and the Ardennes-Alsace. The battalion’s extraordinary valor in the Colmar Pocket earned it a Presidential Unit Citation and the French Croix de Guerre with Palm.

Following the outbreak of the Korean War, the battalion deployed with the 3rd Infantry Division, serving through ten designated campaigns from 1950 to 1953. Providing heavy fire support, the battalion was instrumental during the UN Defensive, the CCF Intervention, and the brutal battles of the Iron Triangle and the Uijongbu Corridor. For its courage under fire, the unit was awarded two Republic of Korea Presidential Unit Citations and the Chryssoun Aristion Andrias (Bravery Gold Medal of Greece).

In 1957, the unit was reorganized under the Combat Arms Regimental System, with the 1st Battalion serving actively with the 3rd Infantry Division until 1971. The unit's most unique chapter began in January 1986, when it was reactivated as a Pershing II tactical nuclear missile battalion under the 56th Field Artillery Command in Neu-Ulm, West Germany. Standing on the front lines of the Cold War, the battalion operated the sophisticated Pershing II, serving as a powerful nuclear deterrent against Soviet forces. However, following the ratification of the historic Intermediate-Range Nuclear Forces (INF) Treaty, the battalion oversaw the destruction of its weapons systems and was inactivated on June 30, 1991.

The battalion was reactivated at Fort Stewart, Georgia, by reflagging the 1st Battalion, 9th Field Artillery Regiment. Assigned to the 2nd Brigade Combat Team, 3rd Infantry Division, the "Battlekings" transitioned into the modern era as a highly lethal armored artillery unit. In the wake of September 11, the battalion deployed multiple times to Iraq and Afghanistan as part of the Global War on Terror, providing heavy, precision strikes in support of coalition maneuvers.

"Battlekings” served as a cornerstone of NATO defense on Europe’s Eastern Flank to counter contemporary threats. Deployed to Pabradė, Lithuania, from 2023 to 2024, the battalion utilized M109A7 Paladin along the NATO-Belarus border. Conducting intensive multinational live-fire exercises, they reinforced Baltic allies’ security. 1-9 FA remains demonstrated rapid deployment readiness as a vital pillar of NATO’s collective defense.