Here are the historical details and information about the 1865 SS Republic Double Eagle $20 coin in NGC MS63 grade with a CAC sticker:

SS Republic Shipwreck: The SS Republic was a sidewheel steamship that operated during the mid-19th century. In October 1865, while en route from New York to New Orleans, the ship encountered a hurricane off the coast of Georgia and sank. The ship carried a cargo of gold and silver coins, including Double Eagles, which were lost at sea.

Recovery: The shipwreck and its cargo remained hidden on the ocean floor for over a century until its discovery by underwater archaeologists and treasure hunters in 2003. The recovery efforts led to the retrieval of a substantial number of gold and silver coins, including the 1865 Double Eagles.

1865 Double Eagle: The 1865 Double Eagle is a $20 gold coin from the Liberty Head Double Eagle series, featuring the familiar design created by Chief Engraver James B. Longacre. The obverse (front) of the coin shows a left-facing Liberty wearing a coronet inscribed with "LIBERTY," and the reverse (back) features an eagle with outstretched wings, holding a shield and arrows in its talons. Above the eagle is the motto "IN GOD WE TRUST," and around the perimeter are stars and the denomination "TWENTY D."

NGC MS63 Grade and CAC: The NGC (Numismatic Guaranty Corporation) MS63 grade indicates that the coin has been professionally graded as "Mint State 63" by NGC, one of the leading coin grading services. An MS63 coin is in "Choice Uncirculated" condition, meaning it exhibits full mint luster and minimal imperfections. The CAC (Certified Acceptance Corporation) sticker is an additional validation of the coin's quality and appeal, making it even more desirable among collectors.