From the time of the Revolutionary War, societies opposed to slavery were organized in the United States. Religious and non-religious groups favored the emancipation of the slaves, but the greatest problem facing those who favored freedom for the slaves was the finding of a suitable environment for the freed, uneducated Negroes. The South which had the greatest number of Negroes would have favored emancipation much more readily if this problem could have been solved satisfactorily. Washington and Jefferson both opposed slavery and Washington in his will provided for the freeing of his slaves upon the death of his wife. Jefferson proposed that the Negroes be freed and then sent out of the United States. Monroe likewise strongly opposed slavery and suggested that the Negroes be allowed to settle in an independent country of their own. In 1816, an American Colonization Society was formed which was granted permission by the Congress of the United States to send emancipated volunteer Negro slaves to Liberia, Africa where they could organize an independent country of their own. The Virginia legislature heartily supported this project. Bushrod Washington, a nephew of George Washington, served as one of the presidents of this national colonization society. John Marshall was the first president of the state branch at Richmond. The capital of Liberia, an independent republic since 1847, is Monrovia, named in honor of James Monroe, who personally urged the establishment of this independent country for Negroes. On March 4, 1825, the "Virginia Dynasty" ended, and President Monroe returned to his home state, Virginia, where he remained until the death of his wife. Virginia had earned the title of "Mother of Presidents" because it had furnished four of the first five Presidents of the United States: George Washington, Thomas Jefferson, James Madison and James Monroe. By 1825, Virginia had lost its first rank in population to New York State, primarily because of the large number of immigrants in the North. The population of Virginia, however, had passed the million mark.