*Corresponding Author: Harold E. Brooks, NOAA/NSSL, Norman, OK 73069.
1Data for the CPI back to 1800 are available at <URL: http://www.lib.umich.edu/libhome/Documents.center/historiccpi.html>
2The most notable tornado, in terms of property damage, prior to the 1890 tornado (estimated at $3 million) is the 1840 Natchez tornado (estimated at $1.3 million). The additional challenges of going even further into the past had led us to decide to start with the 1890 tornado.
3Thirty-six tornadoes are in record from 1890-1924 and two tornadoes are after 1997.
4GNP is used here instead of GDP because of the longer historical record. GDP, which is now the accepted measure of the size of the US economy in keeping with standard international usage, is the market value of all goods and services produced in a country during a year regardless of who owns the production and GNP is the market value of all goods and services produced by residents of a country, regardless of what country they are produced in. Typically, differences in the two measures are less than 1% (Office of the President, 2000).