There were many. The American Colonization Society had members from every State. They sent emigrants to Africa for nearly one hundred years. A report from 1890 states that since the Civil War, 4,138 had been sent to Liberia, and from the beginning 16,136 had been emigrated and another 4,722 slaves rescued (recaptured) making a grand total to date at 21,858 "to whom the Society has given homes in Africa." The American Colonization Society and it's auxiliaries also was involved with a program to teach slave owners to manumit their slaves, and to emigrate freed slaves to free States (they were very successful in Virginia). However, they were no friends of the radical Abolitionist and were eventually distrusted by deep South slave owners as well- not because of their efforts but because the society had too many Northerners running it. Several slave State would drop out of the American Colonization Society and form their own State run groups.

Their belief was as follows...

"Colonizationists believed that a general, immediate, and unconditional emancipation of all the slaves in the Union was impracticable and undesirable: impracticable (1) because there was no constitutional right of the federal government to enact a general emancipation provision, (2) because the States alone having the right to pass emancipation measures would do so only as the public sentiment of each slave State became favorable to emancipation, (3) because public sentiment in the slave States was not yet favorable; undesirable (1) because it was believed that three millions of negro slaves set free at one time would be unable to care for themselves, and would be more wretched than under a system of slavery, (2) because the so-called free negro was not in any true sense free, and it was believed would not become really free until he was taken back to his native country and there, under the supervision of sympathetic governors, was taught self-sustenance and self-government, (3) because of the danger of a race war in the States of the lower South. They recognized slavery to be an evil. The remedy for it they believed to be gradual emancipation, made practicable through (1) cooperation between the different sections of the Union, (2) the education of slaveholders, (3) and the transportation of those manumitted or emancipated. They hoped and believed that such States as Maryland, Virginia, Kentucky, and Tennessee would enact general emancipation measures within a period of time not very remote, and that with these States free, the rest would follow, as the success of emancipation and transportation combined was demonstrated. They hoped to exert a powerful moral influence in favor of emancipation, but were opposed to the use of illegal means or means whose result might be to involve the sections in civil war, or bring about the dissolution of the Union. The gradual abolition of slavery was not to be an incidental object of the Society. It was to be one of the two direct, distinct, and primary objects: (1) to give real freedom to the nominally free American negro, by returning him to his native land and there encouraging his highest development, (2) to exert the most powerful moral pressure consistent with national peace and unity in favor of an emancipation as rapid as practicable, and both universal and absolute.

From its origin, the Society used with eagerness every opportunity to secure the liberation of slaves by offering to transport them to the colony, unless the condition of its treasury was such that it could not afford the expenditure."