Could you tell me if I am right in saying that the Compromise of 1850 abolished the slave trade, but not slavery, in the District of Columbia?

Answer 1

Right.

http://en.wikipedia.org/wiki/Compromise_of_1850#Banning_slave_trade_in_the_District_of_Columbia

Answer 2

Yes, go to the head of the class. THe compromise of 1850 consisted of five bills, the fifth of which did just that. The so-called "Compromise" on this issue was not a compromise as we understand the word, the fifth law caused great consternation amongst the Southern members of congress, but they were outvoted.