He did so by founding the Motion Picture Alliance for the Preservation of American Ideals with a grandiose speech which was typical of those paranoid, Commie-hunting days and would have appealed to his pal, J Edgar Hoover. The movie industry, he said, should be, "held by Americans for the American people, in the interests of America (to further) the American way of life".
The "un-American" troublemakers whom the studio boss feared embraced a wide variety of people. For when Disneyland opened some years later, few blacks, Mexicans, Jews, or Asians found their way on the payroll; the world of Mickey Mouse and Donald Duck was for white patriots.
The passage of time has brought some much needed changes to the Magic Kingdom. Last month the Walt Disney Company announced the appointment to its board of Sidney Poitier, the Oscar-winning actor whom some say had done more than anyone else to free blacks from celluloid stereotypes. Although his role is only that of board member (rather than hands-on mogul) it carries symbolic weight for blacks in the movie business. Even today, every victory counts in an industry in which African Americans occupy a disproportionately small number of top jobs, and which, until a decade or two ago, portrayed most blacks as maids, slaves, musicians or comics.
It also served as a reminder that the progress of blacks in the movie business is decidedly patchy. True, five of the top 40 best paid performers in the US entertainment industry are black - Oprah Winfrey, Bill Cosby, Michael Jackson, Whitney Houston, and Eddie Murphy. There is also a lengthening list of mainstream stars, names that may not "open" movies (pretty well guaranteeing success by their mere presence on the bill) but certainly exert a significant pull at the box office. Denzel Washi ngton, Whitney Houston, Wesley Snipes, Laurence Fishburne, Morgan Freeman, Whoopi Goldberg, Danny Glover, Alfred Woodard and Angela Bassett are all recognised stars. So black actors can and do make big names and big money, but access to the lofty climes where the really big decisions are taken remains elusive.
Several years ago the National Association for the Advancement of Coloured People (NAACP) conducted a survey which found that at six of the major studios there was only one black vice president in charge of feature production, two vice-presidents for TV production, and nine corporate vice-presidents. Although updated figures were unavailable, the picture remains broadly the same - even though America's 31m blacks represent a significant slice of the marketplace, buying more cinema tickets per capita than other demographic groups.
What is less clear is the cause of this phenomenon. Almost no one seems to concur with the view wildly floated by William Cash in a now notorious Spectator article in which he argued that "Brits, Wasps and blacks" are excluded by a "Jewish cabal" which exercises the same sort of petty but insidious influence in Tinseltown as that of the "old school tie" among public school boys in the City of London.
Most lean towards the view that the industry's decisions are primarily influenced by one factor: "In today's market-place any performer, film genre, or ethnic group that proves to be profitable will receive support," writes Gary Null in "Black Hollywood". "In most cases, personal likes and dislikes do not enter into the equation."
But cries of racism against the industry (whether the offending executives be Irish-Americans, Italians, British or Jewish) continue undiminished. Take, for example, the hue and cry raised by Spike Lee in 1992 when Warner Bros refused to provide an extra$5m for Malcolm X after he overran his budget. "Warner Bros didn't come up like they should have come up on this - pure and simple," Lee told Ebony magazine, "And they've come up for a lot of other garbage. But that's par for the course - they come up for white folks. They don't come up for us - ever." Lee turned instead to America's richest black celebrities to bail him out, although an embarrassed Warners eventually chipped in as well.
Although there was some suspicion that Lee was as intent on generating pre-launch publicity as he was interested in seriously tackling an issue, other black film-makers level similar complaints. They acknowledge that the 1990s has produced a wave of impressive black independent movies (Jungle Fever, Menace II Society, Boyz N the Hood, New Jack City, Straight Out of Brooklyn) and a small army of promising directors - John Singleton, Julie Dash, Mario Van Peebles, Robert Townsend, Charles Lane , Reginald and Warrington Hudlin. But, they say, the industry continues to erect barriers.
"Hollywood considers the African American market to be limited," said Ernest Dickerson, director of Juice,a slice-of-life urban drama. "The average Hollywood film is still aimed at the young white male of 25. Even if you're trying to do a black-themed film that's still the audience they think about. You get a lot of watering down of films, where some part is inserted to give the so-called white ``point of view'' - as if they were entering into some sort of strange black world."
Racism is "kind of subtle", he says, but it is present nonetheless Juice, his first movie, was made for $3m, and made £29m domestically. "That's not a bad track record, but I still had to prove myself as a director. Yet I hear plenty of stories where a white director makes a small movie that makes a small amount of money, and the guy then gets a $70m movie."
Does the future offer any hope? Some of the more radical black movie-makers have given up hope that any significant advances are possible within an industry that will always only reflect the prejudices of the mass audience. "We need to get economic power, and gain control," says Saundra Sharp , an independent film-maker.
"We need to find a way of reaching our audience without going through Hollywood. It's already happening, through home videos. I want to see more of that direct approach."Reuse content