This map depicts the Nebaska Territory which includes the modern day states of Montana, Wyoming, Colorado, North Dakota, South Dakota, Kansas, Minnesota, Iowa and Missouri. It was compiled by Lieutenant Gouverneur Kemble Warren for the Army Corps of Topographical Engineers. Born in 1830 Warren graduated West Point in 1850, second in his class. He immediately travelled to the west taking part at first in surveying the lower Mississippi Delta, then the upper Missouri. From 1853 his party was instructed to find the best possible route for a transcontinental railroad. In this role he studied all previous expedition reports back to those of Lewis and Clark. The quality of his work soon earned him recognition and was given command of future explorations. Warren returned to Washington to prepare his reports which culminated in his fine map of the United States from the Mississippi River west to the Pacific Ocean. References: Karrow, R.W. (Mid West) 1-0185; Wheat, C.I. (TM) 871.