One of Hollywood's greatest screen actors, Spencer Bonaventure Tracy (1900-1967) was born on this day in Milwaukee,Wisconsin, the son of a middle-class truck salesman. World War I interrupted hisJesuit prep school plans to enter the priesthood. 

"There were many times my pants were so thin I could sit on a dime and tell if it was heads or tails," Tracy recalled.

After the war, Tracy appeared on Broadway, then was"discovered" by director John Ford.Called an "actor's actor," the mercurial star was well-loved by fans and critics. "Spence is the best we have, because you don't see the mechanism at work," praised friend Humphrey Bogart.

The first to win back-to-back Best Actor Oscars for Captains Courageous (Rudyard Kipling, 1937) and Boys Town (1938), Tracy was able to play drama and comedy with effortless skill. His characters were decent and unpretentious. He was Everyman, yet a stubborn, gruff fighter who cared.

Laurence Olivier in 1981 admitted, "I've learned more about acting from watching Tracy than in any other way. He has great truth in everything he does."

With effortless grace, Tracy hardly seemed to be acting. His show biz advice? "Come to work on time, know your lines, and don't bump into the other actors."

His professional and personal relationship with Katharine Hepburn (his co-star in nine films) lasted 25 years. "Acting is not an important job in the sense of things," he once explained. "Plumbing is."

Cling to what you love.