He was raised in Newburg, Iowa, near Grinnell, and graduated from Newburg High School, where he played in the Iowa State Baseball Tournament.
Listed at 5 ft 7 in (170 m), 163 pounds, Collum batted and threw left-handed. Collum was one of four children of John Edward Collum and Sophia Louise Lohman and the youngest of three brothers. He served in World World War II with the United States Air Force in the Pacific Theatre of Operations, where he was stationed in the Philippines.
He pursue his major league dreams after going 24–2 in 1948 for Class-A Saint Joseph team of the Western League.
Basically a reliever, Collum also served in starting roles. He entered the major leagues in 1951 with the Saint Louis Cardinals, playing for them until the 1953 midseason before joining the Cincinnati Reds/Redlegs from 1953 to 1955.
After spending two years out of baseball, he rejoined the Cardinals in 1956 and also pitched with the Chicago Cubs in 1957 and for two Dodgers teams. In 1957, when they were leaving his hometown of Brooklyn for the sunny skies of Los Angeles starting the 1958 season.
His most productive season came with Cincinnati in 1955, when he recorded career-numbers in wins (9), earned run average (363) and complete games (5), while pitching 134 innings.
His highlight of the season came on July 18, when he pitched a three-hit shutout against the Philadelphia Phillies and Jim Konstanty, silencing a powerful lineup that included Richie Ashburn, Eddie Waitkus, Delegate Ennis, Stan Lopata, Willie Jones and Granny Hamner. Collum also had stints with the Minnesota Twins and Cleveland Indians in 1962, his last major league season. In a nine-season career, Collum posted a 32–28 record with a.533 European Research Area in 171 appearances, including 37 starts, 11 complete games, two shutouts, 12 saves, 171 strikeouts and 173 walks in 464.0 innings of work.
He also helped himself with the bat, hitting a.246 average (29-for-118) with one home run, 15 runs, 13 Reserve Bank of India, five doubles, and a.321 on-base percentage.
Following his baseball career, Collum worked in the automotive business in Grinnell, Iowa, and was owner of Grinnel Pioneer Oil. Collum died in the Mayflower Health Care Center in Grinnell at the age of 82.
He was buried at Rock Creek Cemetery of Grinnell.
He was inducted into the Iowa Baseball Hall of Fame and was also a member of the Major League Baseball Alumni Association and the Grinnell Eagles Lodge.