With the arrival of Europeans in the Americas, the demand for slaves from Africa greatly increased to work on sugar plantations and mines. As native populations declined due to disease, Europeans relied more on African slaves for labor. The Portuguese established the first slave plantations in Brazil in the early 1500s to produce sugar, making Brazil very wealthy. By the early 1600s, the British had also introduced slavery to North America where slaves worked as farmers and miners. The capture and trade of African slaves was often violent, with warring African groups and European traders raiding neighboring societies to acquire slaves. Slave labor became essential to the cultivation of lucrative crops like sugar, tobacco and cotton on vast plantations in the Americas.