Baltimore's African-American population--nearly 27,000 strong and more than 90 percent free in 1860--was the largest in the nation at that time. Christopher Phillips's Freedom's Port, the first book-length study of an urban black population in the antebellum Upper South, chronicles  the growth and development of that community. He shows how it grew from a transient aggregate of individuals, many fresh from slavery, to a strong, overwhelmingly free community less wracked by class and intraracial divisions than were other cities. Almost from the start, Phillips states, Baltimore's African Americans forged their own freedom and actively defended it--in a state that maintained slavery and whose white leadership came to resent the liberties the city's black people had achieved.