On April 19, while Congress was considering joint resolutions supporting Cuban independence, Republican Senator Henry M. Teller of Colorado proposed the Teller Amendment to ensure that the U.S. would not establish permanent control over Cuba after the war. The amendment, disclaiming any intention to annex Cuba, passed the Senate 42 to 35; the House concurred the same day, 311 to 6. The amended resolution demanded Spanish withdrawal and authorized the President to use as much military force as he thought necessary to help Cuba gain independence from Spain. President McKinley signed the joint resolution on April 20, 1898, and the ultimatum was sent to Spain. In response, Spain severed diplomatic relations with the United States on April 21. On the same day, the U.S. Navy began a blockade of Cuba. On April 23, Spain reacted to the blockade by declaring war on the U.S.