President Kennedy set a goal of landing a manned mission on the moon by the end of the 1960s, as stated in his well-known speech to Congress on 25 May 1961 ("I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the earth") and later repeated in his speech at Rice University of 12 September 1962.
NASA achieved the goal when Apollo 11 landed on the moon on 20 July 1969.
Given the Cold War context of the race to the moon, was there any effort made to land Apollo 11 two weeks earlier, so the astronauts were on the lunar surface on the U.S. national day -- 4 July? It would have been a propaganda coup.
Did the orbital mechanics not allow this, or was there absolutely no time to be saved? Surely someone considered this.