Why did Louisiana experience an increase of American migrants during the governorship of Esteban Miró? Louisiana initiated a policy of religious freedom for all people and opened land along the gulf coast for American settlement. They were offered generous land grants in northern and western Louisiana in exchange for their allegiance with Spain. Many colonists loyal to England came to Louisiana seeking a safe-haven after the American Revolution. Americans needed to settle in Louisiana because they were driven off their lands south of the Ohio River by American Indians.