http://en.wikipedia.org/wiki/Admiral_(United_States)
Congress finally authorized nine rear admirals on July 16, 1862, although that was probably more for the needs of the rapidly expanding navy during the
American Civil War than any international considerations.
[1] Two years later Congress authorized the appointment of a
vice admiral from among the nine rear admirals:
David Farragut.
[1] Another bill allowed the
President of the United States to appoint Farragut to admiral on July 25, 1866, and
David Dixon Porter to
vice admiral.
[1] When Farragut died in 1870, Porter became admiral and
Stephen C. Rowan was promoted to vice admiral.
[1] Even after they died, Congress did not allow the promotion of any of the rear admirals to succeed them, so there were no more admirals or vice admirals by promotion until 1915 when Congress authorized an admiral and a vice admiral each for the Atlantic, Pacific and Asiatic Fleets.
[1]
Union blockade - Wikipedia, the free encyclopedia
As the Union fleet grew in size, speed and sophistication, more ports came under Federal control. After 1862, only three ports—
Wilmington, North Carolina;
Charleston, South Carolina; and
Mobile, Alabama—remained open for the 75 to 100 blockade runners in business.
Charleston was shut down by Admiral John A. Dahlgren's South Atlantic Blockading Squadron in 1863. Mobile Bay was captured in August 1864 by Admiral
David Farragut. Blockade runners faced an increasing risk of capture— in 1861 and 1862, one sortie in 9 ended in capture; in 1863 and 1864, one in 3. By war's end, imports had been choked to a trickle as the number of captures came to 50% of the sorties. Some 1,100 blockade runners were captured (and another 300 destroyed). British investors frequently made the mistake of reinvesting their profits in the trade; when the war ended they were stuck with useless ships and rapidly depreciating cotton. In the final accounting, perhaps half the investors took a profit, and half a loss.