Reckord expressed desire to serve in the military, but, at the request of his mother, delayed entry into service until he turned 21. He enlisted in Company D, 1st Maryland Infantry, Maryland National Guard on February 15, 1901, and would eventually rise to command the same company when he was commissioned as a captain in December 1904. As a major, in 1916, Reckord was given command of the 2nd Battalion, 1st Maryland Infantry, which deployed to the Mexican border and served in the Mexican Expedition commanded by Gen. John J. Pershing. When the 29th Infantry Division was created on the eve of World War I in 1917, Reckord was given command of one of its regiments, the 115th Infantry, which saw combat during the Meuse-Argonne Offensive. In 1920, he was appointed Adjutant General of the Maryland National Guard and, in 1934, while still serving as Maryland's Adjutant General, he assumed command of the 29th Infantry Division.