The relevant sentence in the passage is: The 49-and 50-star flags were each flown for the first time at Fort McHenry on Independence Day, in 1959 and 1960 respectively.is the reasoning for what question and answer pair?
Q: Of these proposals, one created by 17-year-old Robert G. Heft in 1958 as a school project received the most publicity. His mother was a seamstress, but refused to do any of the work for him. He originally received a B -- for the project. After discussing the grade with his teacher, it was agreed (somewhat jokingly) that if the flag was accepted by Congress, the grade would be reconsidered. Heft's flag design was chosen and adopted by presidential proclamation after Alaska and before Hawaii was admitted into the Union in 1959. According to Heft, his teacher did keep to their agreement and changed his grade to an A for the project. The 49-and 50-star flags were each flown for the first time at Fort McHenry on Independence Day, in 1959 and 1960 respectively.

Based on this passage, where was the 50 star flag first flown?
A: Fort McHenry