The American Foundation for Equal Rights (AFER) announced Monday that it was closing its doors.

AFER was created to support the case challenging Proposition 8, California's voter-approved constitutional amendment limiting marriage to heterosexual couples.

The case, which reached the Supreme Court in 2013, toppled the ban.

The following year, AFER successfully took on Virginia's restrictive marriage ban.

In June, the Supreme Court ruled that gay and lesbian couples have a constitutional right to marry.

“Nearly six years ago, the American Foundation for Equal Rights (AFER) was created with the specific mission of arguing for marriage equality before the U.S. Supreme Court and to, while doing so, dramatically advance the American conversation on equality,” the group said in an email to supporters.

“And we accomplished that … and so much more.”

AFER went on to endorse the Equality Act, a federal LGBT protections bill introduced by Democrats last months.

(Related: Ted Olson, David Boies endorse comprehensive LGBT non-discrimination legislation.)

“So, while AFER may be closing is doors, we are dedicating all remaining resources to the ongoing battle for full equality,” the group concluded.