1847 Emory Map of the Mexican War Battle of the Rio San Gabriel in Los Angeles

William Hemsley Emory (September 7, 1811 - December 1, 1887) was an American surveyor, civil engineer, and Army officer. Born in Queen Anne's County, Maryland, Emory graduated from the United States Military Academy at West Point in 1831, was assigned to the Fourth Artillery, and resigned from service in 1836 to pursue civil engineering. He returned to the army in 1838 to serve in the newly-formed Army Corps of Topographical Engineers. During the Mexican-American War, Emory served in the Army of the West under the command command of Stephen Watts Kearny. While serving with Kearny, he kept a detailed journal that was then published as Notes of a Military Reconnaissance from Fort Leavenworth to San Diego and soon became an important guidebook for the route to Southern California. After the war, Emory served as part of the team that surveyed the United States-Mexican border. When the American Civil War started, Emory was stationed in Indian Territory and immediately realized the likelihood that Confederates would capture him and his men. To avoid this, Emory quickly secured the services of Black Beaver, the famous Lenape warrior, to guide them out of the territory. Emory and his troops, on their way from Fort Washita to Fort Leavenworth, captured a number of their Confederate pursuers, which were the first prisoners taken during the war. Emory then served in the Army of the Potomac, in the Western Theater, and in the Shenandoah Valley Campaign of 1854. After the war, Emory held the post of commander of the Department of the Gulf during Reconstruction and, in September 1874, President Ulysses S. Grant ordered Emory to New Orleans, where he successfully negotiated a peace with the white supremacist paramilitary organization the White League, which led to the White League being disbanded. Emory married Matilda Wilkins Bache on May 29, 1838 in Philadelphia, with whom he had two sons, both of which served in the United States armed forces. Matilda Bache was Alexander D. Bache's sister. Alexander Bache was one of the most influential superintendents of the United States Coast Survey. More by this mapmaker...

Peter Stephen Duval (1804 - February 8, 1886) was a prominent Philadelphia lithographer. He immigrated to Philadelphia from France in 1831 to take a job as a lithographer at the Philadelphia firm owned by Cephas Childs. In 1837, Childs retired and Duval took over the business. Over the course of the next thirty years, Duval would have several business partners including the Swiss-American engravers Charles and Frederick Bourquin (1808 - 1897). In 1857 his son Steven C. Duval joined the business. Peter Duval retired in 1869 but continued to be involved in his company until his death in 1886. Learn More...