The French transferred Louisiana to Spain in 1763, but this did not change the trading patterns of the eastern groups of Comanches. Spain continued to administer Texas from Mexico City, while Louisiana was placed under the control of the Viceroy of Havana. Meanwhile, French traders from Louisiana continued to use the Wichita to trade for Comanche horses just as before. By 1770 Spain had gained better control of Louisiana, and for the next three years the Spanish used the French traders to make their first peace overtures to the Wichita and eastern Comanches. There was some success with the Wichita, but Comanche raids into Texas continued until a major smallpox epidemic (1780–81) decimated both the Wichita and Comanches.