Charleston’s International African American Museum celebrated a milestone Thursday — they've crossed the goal line of raising $75 million to start construction.

"Setting a $75 million goal was monumental, and many thought it was impossible," former Charleston Mayor Joe Riley told about 150 supporters who gathered near the site in a crowded meeting room at the Charleston Maritime Center to mark the occasion.

Riley, a museum board member, announced the vision for the museum in his 2000 State of the City address and has been the chief fundraiser.

The city kicked in $12.5 million, plus land valued at $25 million. The county pledged $12.5 million and the state $25 million, including an $11 million commitment from the Charleston Naval Complex Redevelopment Authority.

The $25 million in private donations came from hundreds of sources, ranging from $100 from individuals to $10 million from the Lilly Endowment.

The donation that pushed the campaign over the goal line was a $125,000 gift from Herbert L. Drayton III, a Charleston native whose ancestors arrived on a ship near the site of the museum to work on the rice fields at Middleton Plantation. Drayton served in the Air Force and Marine Corps Reserves and is president and CEO of Vertical Holdings, an investment company based in North Charleston.

"It is both fitting and meaningful to recognize Herbert’s pledge today," Museum CEO Michael Boulware Moore said.

It was a day for celebration and thanks but also a time to look ahead to the next phase.

"The big one is done, but we still have other work to do," Moore said. "We will quickly shift to raising money to breathe life into this museum."

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The next mission is to raise $8 million for educational programs and another $6 million to build a $10 million endowment, he said.

Riley said he already has more potential donors lined up to talk with next week.

Tens of thousands of enslaved Africans were unloaded at the wharf on Charleston's waterfront. Museum planners call it a sacred site.

Construction is expected to start early next year, with an opening two years later.

Reach Dave Munday at 843-937-5553.