When Europeans took thousands of Africans from their native land against their will, one can only expect resistance. Through the struggle, enslaved Africans formed slave rhymes, stories, and planned revolts to fight against the tyranny of the slave owners. Enslaved African use forms of rebellion to out smart their masters and sometimes used violence as redemption for their inhumane treatment. A relative increase in the number of Negroes as compared with that of the whites accentuated the danger arising from the former; industrialization and urbanization were phenomena that made the control of slaves more difficult; and, perhaps most important, economic depression, bringing increased hardships, sharpened tempers, forced liquidations of estates (including the human beings involved), and more widespread leasing of slaves, induced rebelliousness. It has been shown that the presence of large numbers of Negroes, free and slave evoked expressions of fear and impelled measures of precaution on the part of the masters from the seventeenth through the nineteenth centuries. Estimates of the total number of slave revolts vary according to the definition of insurrection. For the two centuries preceding the American Civil War (1861-65), one historian found documentary evidence of more than 250 uprisings or attempted uprisings involving 10 or more slaves whose aim was personal freedom. Few of these, however, were systematically planned, and most were merely spontaneous and quite short-lived disturbances by small groups of slaves. Such rebellions were usually attempted by male bondsmen and were often betrayed by house servants who identified more closely with their masters. White Southerners were determined to prevent Black resistances. They mostly used slave patrols to stop and prevent blacks from escaping. "Slave patrols were a common sight on southern roads. Any Black person without a pass from his or her master was captured and returned home to certain punishment"(Out of Many pp.