John Brown was opposed to slavery from birth due to his father's vocal abolitionist views. In 1837, he took an oath to end slavery in the U.S. or die trying. Throughout his life he supported abolitionist causes despite financial struggles. In 1856, his efforts in Kansas raised his profile but in 1859 he led an attempt to take over the federal arsenal at Harper's Ferry to arm a slave rebellion. When local militia and U.S. Marines arrived, Brown was captured, tried, and executed for treason in December 1859. His raid increased sectional tensions and debates over slavery and secession.