A monarchy based on the slave plantation labor of Africans until the late nineteenth century, vast Brazil offered little appeal to European immigrants except in the far south of the country, where smaller plots of arable land became available as the coffee frontier expanded. Facing shortages in slave supply after mid-century, when the British forced the Brazilians to end the trans-Atlantic slave trade, provincial governments attempted to lure European immigrants by granting subsidies to pay for transport and for initial costs of settlements. In 1881, the Imperial government joined in the effort to recruit immigrants who, in addition to providing a replenished work force, could also be counted on to “whiten” the population. Germans predominated among immigrants until 1886, followed by Italians, Poles, and some Japanese until the 1930's, when rising xenophobia led Brazilian officials to curtail immigration and to install a restrictive quota system.