The two men involved in the duel were James Barron and Stephen Decatur.
The Chesapeake-Leopard affair refers to the confrontation between the HMS Leopard and the USS Chesapeake...
...which preceded and helped cause the War of 1812.
This was during the Napoleonic Wars between France and England, while the U.S. was neutral. As such, the U.S. allowed ships from either side to enter their harbors for supplies and/or repairs. Decatur's (commander of the Leopard) orders were to locate and search the frigate, the USS Chesapeake, to find English deserters (sailors).
Salusbury Pryce Humphreys, the commander of the Leopard asked permission to search the Chesapeake for deserters. Commodore James Barron refused. At this point, the Leopard released a volley of fire broadside of the Chesapeake. Barron's crew was only able to return fire one time. Eighteen men were injured (including Barron) and one to three men were killed. (Sources vary with regard to number of men lost.) Barron surrendered immediately.
The crew of the Leopard boarded, took four men off as deserters, and departed. They did not take anything from the ship or harm it further. (Humphreys, commander of the Leopard, also did not accept Barron's surrender.) President Thomas Jefferson was furious (as were American citizens) for this unprovoked attack; they were also angry at how quickly Barron surrendered.
Jefferson could not, at that time, declare war on England, and England knew it. So Jefferson imposed the Embargo Act of 1807 on U.S. trade goods (banning imports and exports), which prohibited the French or the English to use American goods or supplies in repairing their ships or restocking their stores. The embargo...
...for the most part effectively throttled American overseas trade.
This did not last long because in terms of trade, the U.S. suffered more than the English or French; tradesmen and businesses lost thousands and thousands of dollars...(though the smuggling trade was greatly improved for the duration of the embargo). The entire U.S. suffered from the embargo, not just coastal/trading towns.
Later, an investigation was launched into Barron's behavior on the USS Chesapeake at the time of the attack. One source notes...
Barron was convicted of not preparing his ship in advance for possible action...
Another source reports...
Decatur had served on the court-martial that had found Barron guilty of unpreparedness, and had barred him from a command for the next five years.
Commodore Stephen Decatur, Jr., was a part of the panel that voted to court-martial Barron. When Barron returned to duty, many people faulted Barron, but Decatur was the most "vocal" in offering up his criticism. In 1820, Barron challenged Decatur to a duel. Decatur was highly-decorated and greatly praised leader in the American Navy.
Decatur asked Commodore William Bainbridge to be his second in the duel; unfortunately, Bainbridge was not a true friend of Decatur. Barron suggested that they try to reconcile their differences, but the seconds did nothing to promote this. Decatur, an excellent shot, only wanted to wound Barron—which he did, in the the leg (or hip). Decatur was killed by a wound to his abdomen, dying the night of the duel in unimaginable pain.
Stephen Decatur's funeral was attended by Washington's elite, including President Monroe...the justices of the Supreme Court [and]...most of Congress.