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.
Thousands of Americans and immigrants started farms in the West under the provisions of the act. After 1870, settlement became so widespread in the West that it was no longer possible to draw a continuous frontier line. The United States Census of 1890 officially recognized the fact that America's frontier had ended.The settlement of the West brought an end to the American Indian way of life.ore than 25 million immigrants entered the United States between 1870 and 1916. Immigration plus natural growth caused the U.S. population to more than double during the same period, rising from about 40 million to about 100 million.