In the 1950s and 60s the Soviet Union rolled up an impressive series of first in space, including the first satellite, the first animal in space, the first man in space, the first woman in space, the first spacewalk, the first spacecraft to orbit the Moon, the first spacecraft to land on the Moon, and the first spacecraft to land on Venus (after eight tries). Until the Gemini program, the USA was definitely lagging. The Apollo landings on the Moon seemed to end much of the competition. Both countries settled down to creating systems of communications, weather and spy satellites.
After the Soviet Union collapsed, Russia tried to continue its space efforts, but on a reduced scale. President Reagan's dream of a space station was to be transformed into the International Space Station, largely built with the use of America's Space Shuttle.
But the Space Shuttles were supposed to be good for 100 launches each, and there were supposed to be two launches per month. Neither happened. In fact, the Shuttles rolled into retirement after only 136 total launches, and most years saw no more than four launches.
So today the USA has no access to the space station it was largely responsible for building except to ride aboard a Russian Soyuz spacecraft. Even supplies are mostly taken on Russian Progres unmanned vehicles, although American firms such as SpaceX hope to get much of that business in the near future.
Meanwhile, other countries are moving into space. China, Japan, India, Israel, and the European Union have all successfully launched satellites using their own rockets. China has launched their own astronauts as well, and have tested a space station of their own design in orbit. China, India and the Europeans have placed satellites in orbit around the Moon, and Japan has visited an asteroid. China has made public plans for manned landings on the Moon, probably followed by construction of a permanent base there.
The USA claims to be designing new rockets capable of taking crews to the Moon or a nearby asteroid, but with no well-defined plans for either, and with Congress viewing the NASA budget as a prime place to take away funds. The only candidate in this year's Presidential primaries to raise the issue of space was widely ridiculed for it.
So while NASA has held a conference recently on a one hundred year plan for design and launch early in the next century of a probe to nearby stars such as Alpha Centauri and Barnard's Star, America may well find itself incapable of any activities in space, either through neglect or by unfriendly countries.
The most hopeful thought is that American space efforts have always fluctuated from neglect to emergency crash efforts, and may continue to do so. After all, in 1957 the American Secretary of Defense expressed the opinion that he was glad the Soviet Union was the first to launch a satellite, and America would in fact have been first by over a year had not some Pentagon official made sure the top stage of a test rocket in September 1956 had sand instead of rocket fuel.
So in the words of an old sci fi movie, "keep watching the skies", because there is no assurance what will happen next.