(CNN)Here's a look at the Screen Actors Guild. In 2012, a merger was completed between the Screen Actors Guild and the American Federation of Television and Radio Artists (AFTRA). An affiliate of the AFL-CIO, SAG-AFTRA represents, "...actors, announcers, broadcast journalists, dancers, DJ's, news writers, news directors, program hosts, puppeteers, recording artists, singers, stunt performers, voiceover artists and other media professionals." The union has more than 160,000 members.
June 30, 1933 - Articles of incorporation are filed. The guild is formed to get better working conditions for actors.
1935 - Granted an American Federation of Labor charter.
May 1937 - In order to prevent a strike, producers sign a contract with the guild ensuring minimum pay and recognizing the guild.
1943 - Actress Olivia de Havilland sues Warner Brothers studio for extending her contract. She later wins her case.
1945 - The Supreme Court hands down the "de Havilland decision," which declares that studios may no longer hold contract players for more than seven years. This breaks up the system of the studio maintaining control over an actor's career.
1952 - The Guild signs its first contracts for filmed television programs.
December 1, 1952-February 18, 1953 - The first SAG strike is over filmed television commercials. The strike ends with a contract that covers all work in commercials.
August 5-15, 1955 - SAG holds its second strike. This time for increased television show residuals.
March 7, 1960-April 18, 1960 - Third strike over residuals for feature films sold, licensed, or released to television.
December 19, 1978-February 7, 1979 - SAG strikes for better residuals on television advertisements.
July 21, 1980-October 23, 1980 - SAG strikes with the American Federation of Television and Radio Artists (AFTRA). This strike centers on the distribution of profits from pay television and video cassette production.
March 21, 1988 - April 15, 1988 - SAG and AFTRA television commercials strike. The strike is over payment for commercials appearing on cable TV.
February 25, 1995 - The first annual SAG Awards show is held.
May 1, 2000-October 30, 2000 - SAG and AFTRA strike against the advertising industry over commercial work compensation for basic cable and internet.
July 1, 2008 - SAG's TV/Theatrical agreement expires.
November 22, 2008 - Talks between SAG and the Alliance of Motion Picture & Television Producers (AMPTP) end after federal mediation fails to jumpstart a 5 month stalemate.
January 26, 2009 - SAG chief negotiator Doug Allen is fired in a bid by the union's moderate faction to re-enter contract talks with the studios.
April 19, 2009 - SAG leadership split 53% - 47% to accept a new 2-year contract with AMPTP.
June 9, 2009 - Members ratify the two-year contract covering television and motion pictures.
January 29, 2012 - Ken Howard, president of the guild, announces during the SAG awards the merger between SAG and AFTRA has been approved by both groups.
March 30, 2012 - The merger of SAG and AFTRA is completed with more than 80% approval from both unions. The one union is named SAG-AFTRA.
January 27, 2013 - The first Screen Actors Guild Awards is held under the union banner "SAG-AFTRA One Union."
Ralph Morgan 1933, 1938-1940
Eddie Cantor 1933-1935
Robert Montgomery 1935-1938, 1946-1947
Edward Arnold 1940-1942
James Cagney 1942-1944
George Murphy 1944-1946
Ronald Reagan 1947-1952, 1959-1960
Walter Pidgeon 1952-1957
Leon Ames 1957-1958
Howard Keel 1958-1959
George Chandler 1960-963
Dana Andrews 1963-1965
Charlton Heston 1965-1971
John Gavin 1971-1973
Dennis Weaver 1973-1975
Kathleen Nolan 1975-1979
William Schallert 1979-1981
Edward Asner 1981-1985
Patty Duke 1985-1988
Barry Gordon 1988-1995
Richard Masur 1995-1999
William Daniels 1999-2001
Melissa Gilbert 2001-2005
Alan Rosenberg 2005-2009
Ken Howard 2009-present