This Week in the Civil War - 526
In March 1863 California adventurer Ashbury Harpending, with Confederate blessing, joined other San Francisco members of the Knights of the Golden Circle to outfit the schooner J. M. Chapman, as a Confederate privateer.
Their object was to raid Union commerce on the Pacific coast, capturing gold and silver shipments for the Confederacy. Their attempt was detected, and they were seized on the night of their intended departure by the USS Cyane, revenue officers and San Francisco police.
Asbury Harpending was sentenced to ten years in prison and confined at Alcatraz. A few months later President Lincoln issued an amnesty proclamation, granting full pardon to all political prisoners upon the condition that they take and keep the oath of allegiance. Harpending was granted his freedom in February 1864.