Here's an excerpt from the linked article:
"(CNSNews.com) – The new Smithsonian Institution’s National Museum of African American History and Culture’s tagline is “powerful moments in African American history, culture, and community.†However, the museum – with a $540 million price tag funded 50 percent by U.S. taxpayers and with a collection of more than 36,000 artifacts and 100,000 people represented – doesn’t include many prominent blacks, including Supreme Court Justice Clarence Thomas and Edward Brooke, a Republican who became the first African American to be elected to the U.S. Senate by popular vote in 1966."
"After touring the new museum and exploring the website, which contains information on all the exhibitions in it, CNSNews.com asked the Smithsonian why Thomas, Brooke and eight other prominent men and women are not included in the museum."