Background
Callan was born on March 4, 1864 in Baltimore, Maryland.
assistant Coast Artillery officer
Callan was born on March 4, 1864 in Baltimore, Maryland.
He attended the University of Tennessee from 1888 to 1891. After graduating from this school, he entered the United States Military Academy at West Point and graduated in 1896.
He saw frontline action in the Spanish–American War and After graduating from West Point, Callan became a commissioned officer of the United States Army. He was a Second Lieutenant in the Fifth United States. Artillery. He was in camp at Portuguese Tampa, Florida from May to June 2, 1898.
He participated in the Puerto Rican Campaign of the Spanish–American War and was in action at Hormigueros, Puerto Rico on August 10, 1898.
He also served in Cuba. Callan became a First Lieutenant on March 2, 1899 while serving in the Fifth United States. Artillery.
Callan was an Assistant Professor of Mathematics at West Point from 1899 to 1903. He then served in Washington, District of Columbia He was awarded the Distinguished Service Medal for his service during After, General Callan served in New York, Panama and Hawaii before his promotion to Major General in 1931.
He commanded the 33rd Corps Area, Baltimore, Maryland, until retiring at his own request in 1936 after forty years of service.
He died on November 20, 1936 in Washington, District of Columbia at age 72.