Church service
farmed, hunted, and fished while doing odd jobs for both pocket money and LDS Church service. His younger brothers, Dean (1921–1999) and Dale (1925–2003), often tagged along until Leonard served a three-year LDS mission to California. Brostrum was on his church mission when Japan bombed Pearl Harbor on December 7, 1941. After successfully completing his mission, he returned home and joined the U.S. Army in March 1942.