Born on October 17, 1898, in Timpson, Shelby County, Texas, to Sallie Elizabeth Jennings and Caleb Jackson Garrison. He grew up in a well-to-do family that included four brothers, Dan, Homer, Pitser, and Willie, along with two servants.

The United States entered the World War on April 6, 1917, and two months later, on June 5, Halcom registered for the military draft in Shelby County as required by law. His registration card (Form 1) showed his home address as Timpson; he was employed by J. B. Bussey; his mother was dependent upon his support; single; single four years of military service in the Texas Militia (Infantry) and an exemption to the draft claimed but no specific reason given [dependent mother]. Physically, he was described as tall with light brown hair.

His draft notice arrived eleven months later, and Halcom took the oath of enlistment in Center on May 27, 1918, becoming US Army Private Garrison, serial # 3063091. He then, along with other inductees of the day, boarded a railroad train for the 328-mile journey to Camp Travis, San Antonio, Texas, to begin basic training with the 165 Depot Brigade. Following basic, he remained at Camp Travis, reaching the rank of Sergeant on October 6. The war ended on November 11, 1918, and Halcom was honorably discharged on January 10, 1919, and awarded the World War I Victory Medal for his service.

Following the war, he married Miss Eloise McCain in Harrison County on April 17, 1926, and was employed by the telephone company in Shreveport. He later worked for Sinclair Oil in Blanchard, Louisiana, where he retired as Superintendent of the Oil and Gas Department. Halcom died at the age of 71 on February 15, 1970, at Highland Hospital in Shreveport. Funeral services were held two days later at the Blanchard Methodist Church with the Rev. Frank Stage officiating. Burial followed in the Blanchard Memorial Cemetery, Blanchard, Caddo Parish, Louisiana. His wife, Eloise, joined him there in 1986. Day is done, God is nigh.

Bio by Larry E. Hume, VFW Post 8904, Center, Texas