Elmer Francis Layden (May 4, 1903 - June 30, 1973) was an American football player, coach, college athletics administrator, and professional sports executive. He played college football at the University of Notre Dame where he starred at fullback as a member of the legendary "Four Horsemen" backfield. Layden played professionally in the original AFL in 1925 and 1926 with three different clubs, the Hartford Blues, the Brooklyn Horsemen, and the Rock Island Independents. He began his coaching career during the same two seasons at Columbia College in Dubuque, Iowa, now known as Loras College.
Commissioner
In 1941, the National Football League franchise owners voted to change the league's constitution in an attempt to bring all professional football leagues under the authority of one commissioner, who would have similar powers to that of Commissioner of Baseball Kenesaw Mountain Landis. Chicago Tribune journalist Arch Ward was offered the position of commissioner, but he turned it down and suggested Elmer Layden for the position.  Layden was appointed commissioner in February 1941. His appointment was not voted on by the entire league, which upset owners Alexis Thompson, Bert Bell, and Dan Topping. Chicago Bears owner George Halas contended that Layden's hiring was legal because it had been agreed upon by a majority of owners. Layden was signed to a five-year contract with an annual salary of $20,000.  In five years as Commissioner, Layden saw the NFL through the World War II years, in which teams had to use many men of inferior abilities as replacements while most of the regulars were fighting in the war (as did Major League Baseball). During this period a few teams temporarily merged due to lack of manpower, most notably the Pittsburgh Steelers with the Philadelphia Eagles (who were nicknamed the Steagles). The Cleveland Rams ceased operations for the 1943 season.  As NFL commissioner, Layden had once conducted an investigation into a betting scam, without advising the owners, which did not reveal any conspiracy.  Layden's tenure as NFL commissioner came to an end in January 1946. After Brooklyn owner Dan Topping withdrew his team from the league to join the new All-America Football Conference, the remaining owners agreed not to renew Layden's contract, feeling that he was too much of a gentleman and not forceful enough. Layden was succeeded by Bert Bell.

Q: How did Layden become commissioner?
A: it had been agreed upon by a majority of owners.
When did he become commissioner?
Layden was appointed commissioner in February 1941.
Layden was appointed commissioner in February 1941.