CNN Money
By Marc Gunther, Fortune senior writer
July 24 2007: 5:58 AM EDT

Why the change?

"This is a direct result of the organizing that employees have done on the issue of sexual orientation," says Daryl Herrschaft, who oversees the HRC's workplace project. As gay and lesbian employees form internal networking and lobbying groups, they have been able to persuade their employers to protect transgender rights as well.

Broader social forces are also at work. Movies like "Boys Don't Cry" (1999) and "Transmerica" (2005) exposed transgender characters to audiences.