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.
The California Gold Rush was a major factor in expansion west of the Mississippi. That westward expansion was greatly aided by the completion of the Transcontinental Railroad in 1869, and passage of the Homestead Act in 1862.n less than a century, westward expansion stretched the United States from a handful of states along the Eastern Seaboard all the way to the Pacific. The acquisition of Hawaii and Alaska in the mid-19th century assured westward expansion would continue into the 20th century.