He was promoted to first lieutenant and captain during World War I, and served with the 40th Infantry Regiment during its organization and training at Fort Snelling, Minnesota.
After the war, Kramer continued to serve in positions of increasing rank and responsibility, and received promotion to major in 1929 and lieutenant colonel in 1939.
The Japanese surrender in September ended the need for an invasion, so the 97th Division performed occupation duty beginning later that month.
[7] After graduation, Kramer continued to serve in the National Guard while working as a partner in his father's construction company.
[1] In June 1916, Kramer accepted reduction in rank to first lieutenant and reassignment from his inspector's position to serve with his regiment on federal active duty during the Pancho Villa Expedition.
[8] He served with the 5th Nebraska Infantry at Camp Llano Grande near Mercedes, Texas while the unit performed security patrols along the Mexico–U.S.
[8] The start of World War II ended the exchange program, and Kramer returned to the United States in late 1939.
[18] In early 1940, he used his exchange program experiences to provide civilian journalists and U.S. intelligence officials current information about Germany's military capability and capacity.
[1] In December 1944, the 66th Division was en route to France aboard the transports SS Léopoldville and HMS Cheshire.
[21] The ships were five miles from Cherbourg when Léopoldville was torpedoed by a German U-boat; 56 crewmembers died, while the 66th Division sustained losses of 14 officers and 748 soldiers.
[21] Because U.S. troops coordinated activities with French units in the area, Kramer simultaneously commanded all Allied forces in the region as head of the Twelfth Army Group Coastal Sector.
[22] On May 10, a ceremony took place near Caudan, during which Kramer accepted the surrender of General Wilhelm Fahrmbacher's 50,000 troops, along with weapons, vehicles, and other equipment.
[22] After Germany's surrender, the 66th Division moved to Koblenz for occupation duty and to guard German prisoner of war camps,[21] and Kramer was assigned as military governor.
[23] In September 1945, Kramer was assigned to command the 97th Infantry Division, which had left Europe after Germany's surrender and departed the U.S. for the Pacific theater expecting to participate in the planned invasion of Japan.
[22] In a January 1947 speech to a Little Rock, Arkansas civic club, he described the Japanese people as "dirty" and "always hungry" while predicting they would not experience a post-war recovery unless they expanded their farm and industrial production beyond just growing rice.
[30] After retiring from the military, Kramer was a resident of San Antonio, Texas, where he pursued a ten-year career as a field supervisor for the Government Personnel Mutual Life Insurance Company.