Robert Walkup Smith was born on May 13, 1928, in Clarence, Missouri. He graduated from Clarence High School and also the University of Missouri. With the university, he was named to the All-Big Seven baseball teams in 1948, ‘49 and ‘50. 

With the nickname "Riverboat", his first season in professional baseball was with the Scranton Red Sox (Class-A Eastern League) in 1951, shutting out  the opposition twice during the eight-game stretch. He struggled in 1952 and 1953. 

He reportedly quit baseball in 1953 to return to the farm, because he felt he wasn’t getting enough money. After some time off, he returned to Scranton in 1954. He worked exclusively as a reliever, and appeared in 23 games, with an ERA of 3.79.

In 1955 his ERA was 4.25 and his record was 7-5. In 1956 with the San Francisco Seals, he worked more than 174 innings and recorded a 4.44 ERA. He started 25 games and relieved in eight others. He returned to the Seals in 1957 and won eight of his last nine decisions. eventually making the Boston Red Sox in 1958. In July the Sox optioned him to the Minneapolis Millers. With the Millers, he pitched well and was 6-4, with a 2.47 ERA.

The Red Sox brought him back to spring training in 1959, but in March, they traded him to the Chicago Cubs. In May the Cubs traded him to the Cleveland Indians. The Indians sent him to the Pacific Coast League San Diego Padres and Cleveland recalled him to the majors in July. "Riverboat" Smith pitched in 12 games for Cleveland, starting three times and his record was 0-1 with a 5.23 ERA.  It was his last time in the majors.

In mid-October he was one of three pitchers the Indians sold to the Toronto Maple Leafs. He pitched four more years in the minors, all at the Triple-A level in the International League. His final year in professional baseball was 1963 where he pitched for two teams: the Arkansas Travelers and the Atlanta Crackers. 

He returned home to Clarence over the years to work on the farm, and it was while working on the farm that he met his end in a tractor accident that brought death to him on June 23, 2003, in Clarence.