The first naval shot of the Civil War by the U.S. is believed to be by the Revenue Cutter Harriet Lane at the S.S. Nashville outside Charleston Harbor.

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What is lost to history is the S.S. Nashville's title and job early in 1861 and at the time it was fired on was the The United States Mail Steamship Nashville, which had a regular route up and down the south eastern coast of the United States. I have seen histories that identified the Nashville at this time as a Confederate blockade runner which it clearly was not. No, the first shot by federal naval forces in the Civil War was at another United States ship, not a Confederate ship.

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David Upton