About NCMA. NCMA is the national trade association representing the producers and suppliers of concrete masonry products, including concrete block, manufactured stone veneer, segmental retaining walls and articulating concrete block. For over 100 years, the Associationâs mission remains to advance, protect and promote the common interests of its members.
Between 1803 and 1853, the United States almost tripled in size. In the early 1800s, the land west of the United States was very undeveloped.
Louisiana Purchase. History >> Westward Expansion. With the Louisiana Purchase in 1803, the United States acquired a large area of land from the French. It was the single largest purchase of land ever by the United States and doubled the size of the country.