The International African American Museum took a few steps forward after Charleston City Council Tuesday approved contracts for the conceptual design of the building and the exhibit space.

The group also gave final approval to purchase waterfront land for $3.5 million for the museum next to the Charleston Maritime Center. Council's Real Estate Committee unanimously approved that purchase Monday.

The city previously had planned to build the museum on land it owns on the corner of Calhoun and Concord streets. But Charleston Mayor Joe Riley said the new site is better because it provides a view of the harbor, and because it sits on the former Gadsden's Wharf, which was built in 1767 and accepted slave ships from Africa.

The group also voted unanimously to approve $615,000 to hire the architectural firm Moody Nolan, Inc. to develop a conceptual design for the building. That process should take about five months. Moody Nolan is the largest black-owned and operated design firm in the country. It will work corroboratively on the design with Pei Cobb Freed & Partners.

Council also unanimously approved extending a $250,000 contract to Ralph Applebaum and Associates, the group that will design the exhibits. The company's credits include the U.S. Holocaust Museum in Washington, D.C., and the U.S. Capitol Visitor Center.

Councilman Gary White said he supported the museum plans. But, he said, "I have reservations because there's such a large amount of funding needed from the private sector."

Riley said the city can't begin construction until it has raised the $75 million required for the 43,500-square-foot building.

So far, the city and Charleston County each have agreed to contribute $12.5 million.

Riley hopes the state eventually will contribute $25 million, but in its most recent session, the Legislature contributed $7 million.

The city also must raise $25 million from private sources, Riley said. And he's working on that. In a few weeks, he will take a trip to New York to meet with officials at large foundations. He's committed to raising the money to complete the project, he said.

Reach Diane Knich at 843-937-5491 or on Twitter at @dianeknich.