To change view, select desired zoom level and window size from the options below the Zoom View window and then click on the image. The display will be centered where you click. To move up, down, left, or right within a zoom level, click near the edge of the image in the Zoom View or select an area in the Navigator View. The red box on the Navigator View indicates the area of the image being viewed in the Zoom View.

CREDIT: "Mapa de los Estados Unidos de Mexico ['Map of the United States of Mexico']." New York, J. Disturnell, 1847. Geography and Map Division, Library of Congress.