The discovery of gold in the contested area in the late 1850s reignited the dispute. British settlers moved into the region and the British Guiana Mining Company was formed to mine the deposits. Over the years, Venezuela made repeated protests and proposed arbitration, but the British government was uninterested. Venezuela finally broke diplomatic relations with Britain in 1887 and appealed to the United States for help. The British at first rebuffed the United States government's suggestion of arbitration, but when President Grover Cleveland threatened to intervene according to the Monroe Doctrine, Britain agreed to let an international tribunal arbitrate the boundary in 1897.