"While I have never denied my sexuality, I haven't publicly acknowledged it either, until now," said Cook in an essay. "So let me be clear: I'm proud to be gay, and I consider being gay among the greatest gifts God has given me."
While Cook is currently the only openly gay CEO of a Fortune 500 company, there are other top execs for him to thank for leading the charge.
In the essay, first published by Bloomberg BusinessWeek, Cook took the opportunity to not only discuss sexual orientation, but also instances of inequality that affect individuals in the U.S. and around the world. "Part of social progress is understanding that a person is not defined only by one’s sexuality, race, or gender," he said.
"The company I am so fortunate to lead has long advocated for human rights and equality for all," added Cook. "And I will personally continue to advocate for equality for all people until my toes point up."
Here's a look at significant numbers and statistics for Fortune 500 companies and countries around the world on the topics of gender, sexuality and race.
1: The number of openly gay CEOs currently in the Fortune 500 after Tim Cook's announcement today.
5: The number of black CEOs in the Fortune 500. Donald Thompson became the fifth black CEO after taking over at McDonald's (mcd) in 2012.
19: The number of countries where same-sex couples can marry, according to advocacy group Freedom to Marry.
20: The ranking of the U.S. for gender equality by the World Economic Forum in their 2014 Global Gender Gap Index.
27: The number of women CEOs in the Fortune 500. Lisa Su became the 27th female CEO after her promotion to the top position at Advanced Micro Devices (amd) earlier this year.
53: The percentage of LGBT workers nationwide who hide who they are at work, according to the group Human Rights Campaign.
91: The percentage of Fortune 500 companies that mention sexual orientation in their nondiscrimination policies — that's up from 61% in 2002 and just 5% 17 years ago, according to a recent Fortune article.
1973: The year that Katharine Graham of the Washington Post (now Graham Holdings) became the first woman CEO.
1999: The year in which Franklin Raines became the first African-American Fortune 500 CEO by heading up Fannie Mae.
2007: The year John Browne, the former CEO of BP, resigned after being publicly outed as gay by a British tabloid newspaper. He's since written "The Glass Closet" about his experience, and recently penned this feature for Fortune about how corporate America can unlock the closet.