Hurricane climate research is based largely on records from the past 100 years or so. The official Atlantic hurricane record extends back to 1851, but data prior to the middle 20th century need to be treated with particular caution. To better understand climate mechanisms responsible for variations in hurricane activity, it is important to have long-term records. Tropical cyclone impacts in the United States during the first half of the 19th century have been mapped by combining information from historical documents using a Geographic Information System (GIS). The resulting historical hurricane information tool (HHIT) is based on Environmental Systems Research Institute's ArcView GIS. It is available on CD-ROM and online through the Hurricane Climate Institute at Florida State University. The HHIT contributes to greater accessibility of pre-instrumental U.S. hurricane information and can serve as a basis for re-analysis of early U.S. hurricanes.