At 20, he appeared in the World War II morale booster Stage Door Canteen, where he played a star struck serviceman with theater actress and producer Katharine Cornell.
The Los Angeles Times said he stole the film with "his bashful smile and winning ways".

McCallister leapt to fame playing the lead as Sparke in the horse-racing tale Home in Indiana (1944), also starring Walter Brennan and Jeanne Crain.
 This led to a contract with 20th Century Fox.
He followed it with Winged Victory (1944) but then his career momentum was interrupted by war service.

Growing only to 5'6" he found it difficult to find roles as an adult.
He appeared with Edward G. Robinson in 1947's The Red House and had the star role in Thunder in the Valley (1947), and supported June Haver in Scudda Hoo!
Scudda Hay! (
1948).

McCallister had the lead in another animal story The Big Cat (1949) and co-starred with Shirley Temple in The Story of Seabiscuit (1949).
He was in The Boy from Indiana (1950).
At 20, he appeared in the World War II morale booster Stage Door Canteen, where he played a star struck serviceman with theater actress and producer Katharine Cornell. The Los Angeles Times said he stole the film with "his bashful smile and winning ways".
McCallister leapt to fame playing the lead as Sparke in the horse-racing tale Home in Indiana (1944), also starring Walter Brennan and Jeanne Crain.  This led to a contract with 20th Century Fox. He followed it with Winged Victory (1944) but then his career momentum was interrupted by war service.
Growing only to 5'6" he found it difficult to find roles as an adult. He appeared with Edward G. Robinson in 1947's The Red House and had the star role in Thunder in the Valley (1947), and supported June Haver in Scudda Hoo! Scudda Hay! (1948).
McCallister had the lead in another animal story The Big Cat (1949) and co-starred with Shirley Temple in The Story of Seabiscuit (1949). He was in The Boy from Indiana (1950).
Lon McCallister