Castling prohibited, and en passant capture compulsory when only legal move.
The Era (1859-07-10) says that the tourney was open to U.S. composers only, but no such statement is found in the announcement.
More than 18 sets were received (Charleston Daily Courier, vol. LX, 1859-08-31, p. ).
No awarded problems were printed, as the chess column was closed due to pressures of space. The very last installation was published on January 25, 1860 and contained little except the tourney award list.
In the last column, the chess editor (P. A. Aveilhe, Jr.) said that he planned to publish the award-winning sets and additional problems as a book, and called for subscribers. No such work has been found: at present it appears that it was not published as hoped.
In March, 1860, one month later, he started a chess column in the Charleston Evening News. There are indications that some problems from the tournament were published here already in May, which may help clear up some questions around the tourney.
The most important question is probably problem 349 on p. 256 of Alain C. White's book Loyd and his Chess Problems. It is a #4, and is there said to have won 1st prize. According to the list of awards (see above), Loyd's prizes only involved #3. Another publication of the same problem (in Chess Monthly vol. 5:1 (January, 1861), p. 28 does not identify it as a prize-winning problem, which is somewhat unexpected if it was a prize-winner by Loyd.
The question of the extent to which J. P. Barnett was concerned in the #3 prize-winning set is also unanswered, as the best problem award (D) was awarded only to Loyd.