Sanborn Maps were originally created for assessing fire insurance liability and include detailed information about building construction and function, street names and width, natural features, and house and block numbers. The index page features a master index with a map of the entire city divided into 19 hand-colored sections. The sections are numbered to correspond to the individual large scale maps in the bound volume. The Index page also includes an index of streets and addresses and a "specials" index with names of businesses, schools, churches and other points of interest. There is a comprehensive color-coded Key to the symbols and information used on the maps. The Sanborn maps of the city of Trenton originally published in 1874 have been corrected to May 1880, October 1884 and 1885, February and April 1886. The scale of the maps is 1" = 50 '