The establishment of March Air Force Base began in the early 20th century at a time when the United States was rushing to build up its military forces in anticipation of an entry into World War I. In 1917, in response to news from the front lines, Congressional appropriations attempted to back the plans of General George O. Squier, the Army's chief signal officer, to "put the Yankee punch into the war by building an army in the air".

At the same time, the War Department announced its intentions to build several new military installations.
Efforts by Frank Miller, then owner of the Mission Inn in Riverside, California, Hiram Johnson and others, succeeded in gaining War Department approval to construct an airfield at Alessandro Field located near Riverside, an airstrip used by aviators from Rockwell Field on cross-country flights from San Diego.

The Army quickly set about establishing the new air field.
Sergeant Charles E. Garlick, who had landed at Alessandro Field in a Curtiss JN-4 "Jenny" in November 1917, was selected to lead the advance contingent of four men to the new base from Rockwell Field.
On 26 February 1918, Garlick and his crew and a group of muleskinners from nearby Colton, known to be experts in clearing land as well as for their colorful syntax, began the task of excavating the building foundations, and on 1 March 1918, Alessandro Flying Training Field was opened.

On 20 March 1918, Alessandro Flying Training Field became March Field, named in honor of Second Lieutenant Peyton C. March, Jr., son of the Army Chief of Staff, who had been killed when his Curtiss JN-4 "Jenny" crashed in Fort Worth, Texas the previous month.
His crash occurred two weeks after he had been commissioned in the regular United States Army Air Service.

By late April 1918, enough progress had been made in the construction of the new field to allow the arrival of the first troops.
The commander of the 818th Aero Squadron detachment, Captain William Carruthers, took over as the field's first commander and for a time operated out of an office in the Mission Inn.
Within a record 60 days, the grain stubble-covered plain of Moreno Valley had been partially transformed to include twelve hangars, six barracks equipped for 150 men each, mess halls, a machine shop, post exchange, hospital, a supply depot, an aero repair building, bachelor officer's quarters and a residence for the commanding officer.
Eventually March Field saw the construction of some 50 buildings.
It covered over 700 acres and could accommodate up to 1,000 personnel.
Dozens of wooden buildings served as headquarters, maintenance, and officers' quarters.
Enlisted men had to bivouac in tents.

The first flying squadron was the 215th Aero Squadron, which was transferred from Rockwell Field, North Island, California.
Later the 68th and the 289th were also transferred up from Rockwell.
 Only a few U.S. Army Air Service aircraft arrived with squadrons, most of the Curtiss JN-4 Jennys to be used for flight training were shipped in wooden crates by railcar.

March Field served as a base for primary flight training with an eight-week course.
It could accommodate a maximum of 300 students.
In 1918, flight training occurred in two phases: primary and advanced.
Primary training consisted of pilots learning basic flight skills under dual and solo instruction.
After completion of their primary training at Mather, flight cadets were then transferred to another base for advanced training.
Training units assigned to March were:
Post Headquarters, March Field, March 1918 – April 1923
68th Aero Squadron (II), June 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "A", July–November 1918
215th Aero Squadron, March 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "B", July–November 1918
289th Aero Squadron, August 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "C", July–November 1918
293d Aero Squadron, June 1918
Re-designated as Squadron "D", July–November 1918
311th Aero Squadron, June 1918
Re-designated as Squadr
The establishment of March Air Force Base began in the early 20th century at a time when the United States was rushing to build up its military forces in anticipation of an entry into World War I. In 1917, in response to news from the front lines, Congressional appropriations attempted to back the plans of General George O. Squier, the Army's chief signal officer, to "put the Yankee punch into the war by building an army in the air".
At the same time, the War Department announced its intentions to build several new military installations. Efforts by Frank Miller, then owner of the Mission Inn in Riverside, California, Hiram Johnson and others, succeeded in gaining War Department approval to construct an airfield at Alessandro Field located near Riverside, an airstrip used by aviators from Rockwell Field on cross-country flights from San Diego.
The Army quickly set about establishing the new air field. Sergeant Charles E. Garlick, who had landed at Alessandro Field in a Curtiss JN-4 "Jenny" in November 1917, was selected to lead the advance contingent of four men to the new base from Rockwell Field. On 26 February 1918, Garlick and his crew and a group of muleskinners from nearby Colton, known to be experts in clearing land as well as for their colorful syntax, began the task of excavating the building foundations, and on 1 March 1918, Alessandro Flying Training Field was opened.
On 20 March 1918, Alessandro Flying Training Field became March Field, named in honor of Second Lieutenant Peyton C. March, Jr., son of the Army Chief of Staff, who had been killed when his Curtiss JN-4 "Jenny" crashed in Fort Worth, Texas the previous month. His crash occurred two weeks after he had been commissioned in the regular United States Army Air Service.
By late April 1918, enough progress had been made in the construction of the new field to allow the arrival of the first troops. The commander of the 818th Aero Squadron detachment, Captain William Carruthers, took over as the field's first commander and for a time operated out of an office in the Mission Inn. Within a record 60 days, the grain stubble-covered plain of Moreno Valley had been partially transformed to include twelve hangars, six barracks equipped for 150 men each, mess halls, a machine shop, post exchange, hospital, a supply depot, an aero repair building, bachelor officer's quarters and a residence for the commanding officer. Eventually March Field saw the construction of some 50 buildings. It covered over 700 acres and could accommodate up to 1,000 personnel. Dozens of wooden buildings served as headquarters, maintenance, and officers' quarters. Enlisted men had to bivouac in tents. 
The first flying squadron was the 215th Aero Squadron, which was transferred from Rockwell Field, North Island, California. Later the 68th and the 289th were also transferred up from Rockwell.  Only a few U.S. Army Air Service aircraft arrived with squadrons, most of the Curtiss JN-4 Jennys to be used for flight training were shipped in wooden crates by railcar.
March Field served as a base for primary flight training with an eight-week course. It could accommodate a maximum of 300 students. In 1918, flight training occurred in two phases: primary and advanced. Primary training consisted of pilots learning basic flight skills under dual and solo instruction. After completion of their primary training at Mather, flight cadets were then transferred to another base for advanced training. Training units assigned to March were:
Post Headquarters, March Field, March 1918 – April 1923
68th Aero Squadron (II), June 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "A", July–November 1918
215th Aero Squadron, March 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "B", July–November 1918
289th Aero Squadron, August 1918 (transferred from Rockwell Field, California)
Re-designated as Squadron "C", July–November 1918
293d Aero Squadron, June 1918
Re-designated as Squadron "D", July–November 1918
311th Aero Squadron, June 1918
Re-designated as Squadr
March Air Reserve Base