African-Americans are a major ethnic group in the United States. Most African-Americans are descendants of enslaved Africans brought to the Thirteen Colonies from the 17th to the 19th centuries, while the term also includes any Americans of African descent in general. With a population of 42,020,743, they make up 13.6% of the US population, and they have been an important part of US history. African-Americans led the Civil Rights movement of the 20th century, and in 2009 President Barack Obama was the first African-American to be elected President of the United States. 78% of African-Americans are Protestant, 13% atheist, 5% Catholic, and 1% Muslim (mostly Sunni or Ahmadiyya).