Well, at least America won the Space Race of the 1960s, putting a man on the moon before the decade was over, as president Kennedy had declared.
This was quite an achievement.
Then in the early 1970s came the economic recession and oil crisis, failure to win the war in Vietnam etc, stuff that probably affected the space projects.
On the other hand NASA had great success with the Space Shuttle in late 1970s/ 1980s, at least until 1986 when Challenger blew up shortly after take-off, killing all of the crew.
This was of course a big tragedy and set-back for the shuttle project.