African-American history is the portion of American history that specifically discusses the African-American or Black American ethnic groups in the United States. Most African Americans are the descendants of captive Africans held in the United States (or British controlled territories that would become the United States) from 1555 to 1865. Blacks from the Caribbean whose ancestors immigrated, or who immigrated to the U.S., also traditionally have been considered African-American, as they share a common history of predominantly West African or Central African roots, the Middle Passage and slavery. African Americans have been known by various names throughout American history, including colored and Negro, which are no longer generally accepted in English. Instead the most usual and accepted terms nowadays are African American and Black, which however may have different connotations (see African American#Terminology). The term person of color usually refers not only to African Americans, but also to other non-white ethnic groups. Others who sometimes are referred to as African Americans, and who may identify themselves as such in US government censuses, include relatively recent Black immigrants from Africa, South America and elsewhere. African-American history is celebrated and highlighted annually in the United States during February, designated as Black History Month. Although previously marginalized, African-American history has gained ground in school and university curricula in recent years.