“If signed, Iowa will become the first state in American history to remove a protected class from its Civil Rights Act,” wrote Erin Reed, a journalist and trans rights advocate, “setting a dangerous precedent for broader rollbacks of anti-discrimination protections.”

The bill created explicit legal definitions of female and male based on the reproductive organs with which they were born.

The Iowa Senate and House debated for several hours before passing the legislation overwhelmingly along party lines. The governor is expected to sign the bill.