The Alto Velo Claim was a claim against the Dominican government by American adventurers ejected on the eve of the unsuccessful Spanish reoccupation (1861–1865) of the guano island called Alto Velo Island located some fifteen miles south of the Dominican Republic. It has significance in United States political history primarily because former Secretary of State Jeremiah S. Black resigned as defending counsel in the impeachment trial of President Andrew Johnson in 1868 when the latter would not order Secretary of State William H. Seward to approve the claim.
The U.S. has never renounced the claim and documents prepared by the State Department dispute the claim of the Dominican Republic to this territory (Report of the Secretary of State on the Claim of Patterson and Murguiondo, with a Further Argument of the Claimants, 1868).