Captain America/Steve Rogers (Chris Evans), the paradigm of the United States - a man that turns out to be the idol of the nation - has to face, now, a new chapter of his life where he has to face a new enemy and save some citizens from the destruction. This is the second movie of this saga where there's a good plot but with barely different, or not so used sequences or scenes of the superheros movie, in general. However there are a couple or three scenes where the movie seems closer to real live, for example the Apple Store scene, the monologue of a computer or some comedic scenes.
As for the story, Steve Rogers, as said, needs to solve a new problem that has emerged from the bowels of Shield, where he works. Helped by always an astute and ingenious Black Widow/Natascha (Scarlett Johansson) and another friend Rogers will need to find out what's going on and face a very powerful enemy, the Winter Soldier. The film has also story about the conspiracy of the 80's in America (also nowadays), and Robert Redford character looks like a Nixon or Reagan.
So, to conclude, it can be said this quite a long film for the story that has to tell but that it also has some things that Marvel does to differentiate their films from all the others and above all to make every superhero look different in some way - just compare this films with the Iron Man ones. It is well written but it has a lack of surprise on the screenplay that makes it just one more feature film to watch once and some other time if you turn to watch it but not more.
Everything is prepared for The Avengers.