Althea Gibson, who was Serena Williams a good 40 years before Serena, is the subject of a new documentary that will be shown at film festivals this spring.

Directed by Rex Miller, "Althea" is a documentary that has been in the works for five years. Miller is the son of Millicent Miller, herself a tennis player who once played Gibson at the Merion Cricket Club in Pennsylvania in 1960.

Raised in Harlem, Gibson's story is one of the most amazing in American sports history. She won 12 Grand Slam titles - five singles, six women's doubles and one in mixed doubles.

She was the first African-American to play at the US National Championships (precursor to the US Open), doing so in 1950. She was also the first frican-American to win a Grand Slam title, winning Roland Garros' singles and doubles crowns in 1956. She would later be the first black woman to appear on the covers of Sports Illustrated and Time.

Amazingly, she also broke the color barrier on the Ladies Professional Golf Association tour, doing so at age 37 in 1964.

Details of the film along with a preview can be found here.