African American is a politically correct term some use to describe the ethnic background of Americans with African ancestry. The great majority of African Americans are descended from Africans brought to North America as slaves beginning four centuries ago. Others (like Colin Powell) were twentieth century immigrants from the West Indies or Africa. Many American conservatives believe that the use of terms such as "African-American" or "Mexican-American," collectively referred to as "hyphenated Americanism," make the mistake of "putting America second" and emphasize racial differences over common national identity 
The preferred terminology changes constantly. Currently "black" and "African American" are in favor, and "Afro-American" and "Negro" are out of favor. The situation before 1960 was just the reverse. "Colored" was popular until the 1950s, but now is generally out of favor except among some leftist groups.
see Black history
Blacks were originally brought to America to serve as slaves in southeastern states on large-scale plantations. During the Civil War, all slaves were freed by Abraham Lincoln though the Emancipation Proclamation, the Thirteenth Amendment, and some state actions. During Reconstruction the Freedmen (freed slaves) gained citizenship and civil and political rights, including the right to marry, move about, and keep their wages.
The system of sharecropping instituted after the end of the war left most Freedmen poor, while the Jim Crow policies of racial segregation that were implemented after the end of Reconstruction limited their civic and political rights.
Blacks left the rural south in two waves, the first around 1915-20, the second coming after World War II when machinery ended the need for large numbers of people to pick cotton by hand. The migrants headed to the large cities of the North and West, and also in the South, moving from very poorly paid farm work to wage labor.
Blacks tended to support the Republican Party from the 1860s to the 1960s, but few who lived in the South voted--some states even stopped people of African ancestry voting by the use of literacy tests, poll taxes and other measures. The New Deal provided large-scale relief for blacks during the Great Depression. Some black Republican organizations, as in Chicago, switched overnight to the Democrats. This sudden change is often attributed to the leftist sentiments that were growing in the late twentieth century. The Voting Rights Act of 1965 allowed blacks to vote in the South, and has been vigorously enforced. Since 1964 blacks have voted 85% to 95% for Democratic presidential candidates, with an occasional black Republican elected to state office.
Among African-Americans, religiosity is very high, and the standard practice since Reconstruction is for black ministers to be community spokespersons, and political power brokers; they often run for office. The great majority of African Americans are Protestants, with their own Baptist, Pentecostal, and Methodist churches. A few are Muslims.
Racial registration and anti-miscegenation laws
In the early 20th centiry some states, not only in the South, adopted racial registration policies and implemented laws against the mixing of black and white people. These "anti-miscegenation" laws were only finally ended in the federal case Loving v. Virginia, when a mixed race couple successfully challenged all laws against mixed marriage in the states.
- ↑ http://www.americanthinker.com/2010/05/on_becoming_an_unhyphenated_am.html
- ↑ The Pluralism Project at Harvard University Twenty-four percent of American Muslims are black, according to American Muslim Council's Zogby poll of August 2000.