On July 1, 1882, John Wesley Powell appointed Gannett as the chief geographer in charge of the topographic mapping division of the USGS, a position he held until 1896. Around 1884, he persuaded various organizations doing the surveys, including the railroads, to begin using similar datums so the data could interconnect. As the chief geographer, he oversaw work on the topographical atlas of the United States. He also served as a geographer for the 11th Census in 1890 and the 12th Census in 1900. In 1890, he and Thomas Corwin Mendenhall of the U.S. National Geodetic Survey campaigned to establish the United States Board on Geographic Names to create official names for locations in the United States. He was named to the newly created Board on Geographic Names by President Benjamin Harrison in Executive Order No. 28. In 1896, his last year with the USGS, he started the use of the benchmark. In 1899, he was invited on the Harriman Alaska Expedition. In 1899, he was appointed the assistant director of the Census of the Philippines and Puerto Rico, the Philippines again in 1902, and Cuba in 1906. In 1909 he was named chairman of a special committee to examine and verify the records of Robert E. Peary in the controversy with Frederick Cook over who was the first to reach the North Pole. Publications Gannett's published works are geographical and statistical. Although he did not public many works in geomorphology and physical geology, he offered valuable suggestions. For example, he recognized hanging valleys and their importance to interpreting a geological setting. He was issued a gazetteer for eleven states and was a contributor to Baedecker's Guide to the United States, Encyclopedia Britannica, and The New International Encyclopedia. Following are some Gannett's publications: The West with R. P. Porter and W. A. Jones (1882) Scribner's Statistical Atlas with F.W. Hewes (1883). "Dictionary of Altitudes in the United States." United States Geological Survey Bulletin No. 5(1884) "Dictionary of Altitudes in the United States. 2nd edition." United States Geological Survey Bulletin No. 70 (1884) ‘Boundaries of the United States and of the Several States and Territories, with a Historical Sketch of the Territorial Changes,” United States Geological Survey Bulletin No. 13 (1885) The Building of a Nation (1893) A Manual of Topographic Methods. U.S. Geological Survey Monograph 22 (1893) A Manual of Topographic Surveying (1895) Commercial Geography with Garrison and Houston(1895) The