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 Missouri Crisis. Another stage of U.S. expansion took place when inhabitants of Missouri began petitioning for statehood beginning in 1817. The Missouri territory had been part of the Louisiana Purchase and was the first part of that vast acquisition to apply for statehood. By 1818, tens of thousands of settlers had flocked to Missouri, including slaveholders who brought with them some ten thousand slaves.