This led to retaliation on the part of the Negroes. There had not been in the United States before this many attempts at insurrection. The slaves were distributed over a wide territory, and before they became intelligent enough to cooperate the chance of emancipation was held before them. Several small insurrections are alluded to in South Carolina early in the eighteenth century, and one by Cato at Stono in 1740 caused widespread alarm. The Negro plot in New York in 1712 put the city into hysterics. There was no further plotting on any scale until the Haytian revolt, when Gabriel in Virginia made an abortive attempt. In 1822 a free Negro, Denmark Vesey, in South Carolina, failed in a well-laid plot, and ten years after that, in 1831, Nat Turner led his insurrection in Virginia and killed fifty-one persons. The result of this insurrection was to crystallize tendencies toward harshness which the economic revolution was making advisable. A wave of legislation passed over the South, prohibiting the slaves from learning to read and write, forbidding Negroes to preach, and interfering with Negro religious meetings. Virginia declared in 1831 that neither slaves nor free Negroes might preach, nor could they attend religious service at night without permission. In North Carolina slaves and free Negroes were forbidden to preach, exhort, or teach "in any prayer meeting or other association for worship where slaves of different families are collected together" on penalty of not more than thirty-nine lashes. Maryland and Georgia and other states had similar laws. The real effective revolt of the Negro against slavery was not, however, by fighting, but by running away, usually to the North, which had been recently freed from slavery. From the beginning of the nineteenth century slaves began to escape in considerable numbers. Four geographical paths were chiefly followed: one, leading southward, was the line of swamps along the coast from Norfolk, Virginia, to the northern border of Florida. This gave rise to the Negro element among the Indians in Florida and led to the two Seminole wars of 1817 and 1835. These wars were really slave raids to make the Indians give up the Negro and half-breed slaves domiciled among them. The wars cost the United States ten million dollars and two thousand lives. The great Appalachian range, with its abutting mountains, was the safest path northward. Through Tennessee and Kentucky and the heart of the Cumberland Mountains, using the limestone caverns, was the third route, and the valley of the Mississippi was the western tunnel.