German Federal Republic was formed in 1949, from the three western zones (American, British and French). The country became fully independent in 1955.
During the 1950's and 1960's, West Germany underwent an economic boom and became one of the world's major industrial powers. During the 1970's, West Germany normalized relations with its communist neighbors and dramatically expanded its trade with Eastern Europe.
Reunification of the two Germanys was always the highest priority of the West German government. With the fall of the East German communist regime in 1989, reunification proceeded rapidly, and by the end of 1990 the German Federal Republic and the German Democratic Republic had again become one nation.

West Germany stamps:

 

 

and stamps of united Germany: