The central issue facing President Van Buren was the Panic of 1837, a sustained economic downturn that began just weeks into his presidency. Van Buren opposed any direct federal government intervention and cut back federal spending to maintain a balanced budget. He also presided over the establishment of the independent treasury system, a series of government vaults that replaced banks as the repository of federal funds. Van Buren continued the Indian removal policies of the Jackson administration, as thousands of Native Americans were resettled west of the Mississippi River during his presidency. He sought to avoid major tensions over slavery, rejecting the possibility of annexing Texas and appealing the case of United States v. The Amistad to the Supreme Court. In foreign affairs, Van Buren avoided war with Britain despite several incidents, including the bloodless Aroostook War and the Caroline Affair.