The Equal Employment Opportunity Commission on Thursday filed the first-ever lawsuits seeking to protect transgender workers under the Civil Rights Act of 1964—the latest move in a growing effort to protect the rights of transgender people at work.

The two lawsuits, filed separately in federal courts in Florida and Michigan, accuse two employers of discriminating against transgender employees. In the Florida case, Lakeland Eye Clinic fired Brandi Branson, after she started dressing as a woman. The clinic hired Branson in 2010, when she presented as a man. When terminating Branson, the clinic said it was eliminating her position, but it hired a male employee to replace Branson two months later, the lawsuit claims.

In the Michigan case, a funeral home allegedly fired funeral director and embalmer Amiee Stephens two weeks after she told her employer and colleagues that she was transitioning to a woman and would start dressing in female attire.

The lawsuits are based on a April 2012 decision by the EEOC that effectively expanded the meaning of “sex discrimination” in Title VII of the Civil Rights Act to include discrimination against transgender people.

While the lawsuits are historic in that they are the first filed by the EEOC under Title VII, when it comes to recognizing and protecting transgender workers, the agency is actually behind courts that have been increasingly recognizing the workplace protections of transgender workers under that section of the Civil Rights Act for the past decade, says Marcia McCormick, professor of employment law at St. Louis University School of Law.

In 2011, for instance, the Eleventh Circuit Court of Appeals found that Vandy Beth Glenn, an editor and proofreader of bill language for the Georgia General Assembly, was the victim of discrimination when her employer fired her after she disclosed that she planned to transition from male to female. In 2004, the Sixth Circuit Court of Appeals found that a transgender firefighter who was suspended for not being “masculine enough” had an actionable discrimination claim under Title VII. Some district courts have made reached the same determination. In 2008, the U.S. District Court for the District of Columbia found in favor of Diane Schroer, a former Army Colonel who transitioned from male to female, in her discrimination lawsuit against her employer The Library of Congress.

While transgender employees have found some success in the courts, they’d have a better chance at workplace protection, McCormick says, if Congress passed the Employment Non-Discrimination Act, a pieces of legislation that’s been introduced in every Congress but one for the last two decades.

The initial 1994 version of the law would have made it illegal to discriminate against employees in all aspects of employment based on a person’s actual or perceived sexual orientation. Language protecting against discrimination based on gender identity was added in 2007. The Senate passed ENDA in November 2013 and it’s been stuck in the House of Representatives ever since.

A patchwork of state and local laws already protect gay and transgender workers in this way, but there are 29 states with no such guidelines. Passing ENDA would serve as an added statute that grants discrimination protection to transgender workers and it would fill in some of Title VII’s holes. Title VII doesn’t protect the status of being gay, lesbian, or transgender; it protects against discrimination based on the differences between men and women and sex stereotyping—whether someone is masculine or feminine enough, McCormick says. ENDA would cover those gaps. (ENDA does have downsides; it only covers companies with at least 15 employees and exempts religious employers.)

But even without ENDA’s passage, McCormick says, “in terms of things like reasons not to be hired and fired, pay questions and benefits, transgender employees have had a lot of success with relief under Title VII.” That’s important progress, considering that a 2011 survey from The National Center for Transgender Equality and The National Gay and Lesbian Task Force found that 90% of respondents, who were transgender, reported experiencing “harassment, mistreatment or discrimination on the job or took actions like hiding who they are to avoid it.”

Where transgender workers do not have protection, McCormick says, “are accommodations issues, like bathroom access and other situations where privacy is involved.”

In 2007, for instance, the Tenth Circuit Court of Appeals upheld the firing of a transgender Utah Transit Authority bus worker based on her desire to use women’s restrooms while on her route.

“Courts have allowed companies to segregate on the basis of biological gender and cultural norms,” McCormick says.