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.
Greater progress was made by Spanish colonizers on the other side of the continent. In 1598, Don Juan OÃ±ante led 500 men from Mexico northward into Pueblo lands in present-day New Mexico. The invaders brought with them a labor system known as the encomienda, which had originally developed in Spain.