Citigroup Inc.'s appointment of Jane Fraser as its next chief executive on Thursday was celebrated on Wall Street as the first woman to lead one of the top U.S. banks. Yet this is a glass ceiling that corporate America shattered decades ago.

It was 1972 when the Washington Post, then a Fortune 500 company, named Katherine Graham as its CEO. While progress for female leaders has been slow, 36 of the Fortune 500 companies are now run by women, including automaker General Motors Co., chocolate-maker Hershey Co and Northrop Grumman Corp., according to corporate governance services firm BoardEx.

But the male-dominated financial services industry has fared poorly. Even beyond the major banks, only four of the 200 largest public U.S. financial services companies — Synchrony Financial, Franklin Resources Inc., Nasdaq Inc. and CIT Group Inc. - have female CEOs, according to BoardEx.