Union naval blockad "Milestones: 1861–1865 - Office of the Historian" https://history.state.gov/milestones/1861-1865/blockade https://history.state.gov/milestones/1861-1865/blockade "Milestones: 1861-1865 - Office of the Historian" https://history.state.gov/milestones/1861-1865/blockade https://history.state.gov/milestones/1861-1865/blockade https://history.state.gov/milestones/1861-1865/blockade blockaded history.state.gov "Milestones: 1861–1865 - Office of the Historian" https://history.state.gov/milestones/1861-1865/blockade "Milestones: 1861-1865 - Office of the Historian"