Columbia subject headings:
Mexico--Economic conditions--1540-1810.
Mexico--Economic conditions--19th century.
Roads--Mexico--History--18th century.
Roads--Mexico--History--19th century.
Transportation--Mexico--History--18th century.
Transportation--Mexico--History--19th century.
Harvard subject headings:
Mexico--Economic conditions--1540-1810.
Mexico--Economic conditions--19th century.
Roads--Mexico--History--18th century.
Roads--Mexico--History--19th century.
Transportation--Mexico--History--18th century.
Transportation--Mexico--History--19th century.
Princeton subject headings:
Mexico--Economic conditions--1540-1810.
Mexico--Economic conditions--19th century.
Roads--Mexico--History--18th century.
Roads--Mexico--History--19th century.
Transportation--Mexico--History--18th century.
Transportation--Mexico--History--19th century.