Amazon.com founder Jeff Bezos gave $2.5 million today to Washington United for Marriage, a coalition fighting for same-sex marriage rights in the Pacific Northwest state.
The donation – which comes from Bezos and wife MacKenzie – gives WUM $5 million to lobby for Referendum 74 in this November’s election.
“I am thrilled by Jeff and MacKenzie’s staggeringly generous donation,” Jennifer Cast, WUM’s volunteer finance co-chairwoman, said on the group’s website.
“Their support of our efforts to approve R74 comes at an important time and will have great impact. I am deeply grateful to both of them as this donation is going to help us make history,” said Cast, who spent seven-plus years at Amazon.com.
The amount tops similar contributions from Microsoft founder Bill Gates and CEO Steve Ballmer, who each donated $100,000 to the cause, The Associated Press reported.
Washington State Gov. Christine Gregoire signed the bill into law earlier this year, but Preserve Marriage Washington collected 240,000 signatures and forced the referendum; it was to take effect in early June.
More from GlobalPost: Gregoire signs Washington’s gay marriage bill into law
The donation makes the Bezos family one of America’s largest same-sex marriage backers, The New York Times said.
WUM hopes to make Washington the first state to pass a same-sex marriage law at the polls.
While six states have legalized gay marriage, no state has won when the issue comes to a vote, The Times said.
“The extraordinary contribution … will make an enormous difference for our campaign to defend Washington’s marriage law,” said WUM’s campaign manager, Zach Silk. “While it provides an amazing base for the work ahead, we hope it spurs others to invest because we’re a long way from November and we face opponents with deep pockets who are committed to spending millions to defeat us.”
According to Forbes, Bezos is worth an estimated $18.4 billion and is number 26 in the world.
The 48-year-old Seattle native founded Amazon.com in 1994.
More from GlobalPost: Bezos to raise Apollo 11 engines from ocean floor