Thompson’s retirement, which was announced on Wednesday and came less than a week after McDonald’s (MCD) reported a fifth consecutive quarter of declining same-store sales in the U.S., will hurt CEO diversity among the top Fortune 500 companies. Thomson, an executive with 24 years of experience at McDonald’s, became CEO in 2012 and was replaced by another insider, Steve Easterbrook. Easterbrook is white.

Thompson’s exit has not been viewed as racially motivated in any way as McDonald’s has faced a ton of challenges. For example, 2014 became the first year since 2002 that the fast-food giant suffered a global decline in sales at outlets open for at least a year.

But his retirement will temporarily diminish diversity for the Fortune 500. C-suites are overwhelmingly white, as Fortune has previously reported. J.C. Penney (JCP) will help improve diversity later this year, when Marvin Ellison, an African American, will become CEO in August. Ellison had worked at Home Depot (HD) and Target (TGT).

Here is a look at the other four Fortune 500 companies that are led by an African American. All but one were insiders that worked their way up the ranks to eventually claim the top leadership role.

Kenneth Frazier — Merck (ranked 65)

Kenneth Frazier, chairman and CEO of Merck (MRK), first joined the pharmaceutical company in 1992 as an executive and worked his way up the ranks with a number of promotions within the legal department. He eventually became Merck president in 2010 and became CEO less than a year later. Prior to joining Merck, Frazier was a partner at a Philadelphia law firm. Frazier received a bachelor's degree from Pennsylvania State University and holds a J.D. from Harvard Law School.

Kenneth Chenault — American Express (90)

Financial services firm American Express (AXP) has been led by Chairman and CEO Kenneth Chenault since April 2001. He joined the company in 1981 and was named president of the U.S. division of American Express Travel Related Services in 1993. He also previously served as chief operating officer. Chenault serves as a board member at two of the U.S.'s largest firms, International Business Machines Corp. (IBM) and Procter & Gamble (PG).

Roger W. Ferguson Jr. — TIAA-CREF (95)

Roger W. Ferguson Jr., who joined financial services provider TIAA-CREF in 2008, previously served as former vice chairman at the Federal Reserve. He was the only Fed governor in Washington D.C. when 9/11 occurred, and thus he led the Fed's initial response to the terrorist attacks and helped keep the U.S. financial system functioning. He also served as an executive at reinsurance company Swiss Re. Ferguson began his career as an attorney in New York City.

Ursula Burns — Xerox (137)

Xerox has been led by Ursula Burns since July 2009, and shortly after, made the largest acquisition in history with the $6.4 billion purchase of Affiliated Computer Services. Burns, like most of the CEOs on this list, was an insider at Xerox as she had worked at the company since 1980 when she first served as a mechanical engineering summer intern. Burns worked her way up the ranks and also helped Xerox restructure its operations under the direction of then-CEO Anne Mulcahy. Burns serves on the boards of American Express and Exxon Mobil (XOM).