were slaves, who could only travel to the church and attend services with the permission of their owners. Following slave revolts in the early 19th century, including Nat Turner's Rebellion in 1831, Virginia passed a law requiring black congregations to meet only in the presence of a white minister. Other states similarly restricted exclusively black churches or the assembly of blacks in large groups unsupervised by whites. Nevertheless, the black Baptist congregations in the cities grew rapidly and their members numbered several hundred each before the Civil War (see next section). While mostly led by free blacks, most of their members were slaves. In plantation areas, slaves organized underground churches and hidden religious meetings, the "invisible church", where slaves were free to mix evangelical Christianity with African beliefs and African rhythms. With the time, many incorporated Wesleyan Methodist hymns, gospel songs, and spirituals. The underground churches provided psychological refuge from the white world. The spirituals gave the church members a secret way to communicate and, in some cases, to plan a rebellion. Slaves also learned about Christianity by attending services led by a white preacher or supervised by a white person. Slaveholders often held prayer meetings at their plantations. In the South until the Great Awakening, most slaveholders were Anglican if they practiced any Christianity. Although in the early years of the First Great Awakening, Methodist and Baptist preachers argued for manumission of slaves and abolition, by the early decades of the 19th century, they often had found ways to support the institution. In settings where whites supervised worship and prayer, they used Bible stories that reinforced people's keeping to their places in society, urging slaves to be loyal and to obey their masters. In the 19th century, Methodist and Baptist chapels were founded among many of the smaller communities and common planters. During the early decades of the 19th century, they used stories such as the Curse of Ham to justify slavery to themselves. They promoted the idea that loyal and hard-working slaves would be rewarded in the afterlife. Sometimes slaves established their own Sabbath schools to talk about the Scriptures. Slaves who were literate tried to teach others to read, as Frederick Douglass did while still enslaved as a young man in Maryland. Free blacks Free blacks in both northern and southern cities formed their own congregations and churches before the end of the 18th century. They organized