<P> Yellow fever was a threat in New Orleans and south Louisiana virtually every year, during the warmest months . Among the more prominent victims were: Spanish colonial Governor Manuel Gayoso de Lemos (1799); the first and second wives (d . 1804, 1809) of territorial Governor William C.C. Claiborne and his young daughter (1804); one of New Orleans' most important early city planners Barthelemy Lafon (1820), architect Benjamin Henry Latrobe and one of his sons (1820, 1817, respectively), who were in New Orleans building the city's first waterworks; Jesse Burton Harrison (1841), a young lawyer and author; Confederate Brig. Gen. Young Marshall Moody (1866); architect James Gallier, Jr. (1868); and Confederate Lt. Gen. John Bell Hood and his wife and daughter (1879). </P> <P> A ship carrying persons infected with the virus arrived in Hampton Roads in southeastern Virginia in June 1855 . The disease spread quickly through the community, eventually killing over 3,000 people, mostly residents of Norfolk and Portsmouth . The Howard Association, a benevolent organization, was formed to help coordinate assistance in the form of funds, supplies, and medical professionals and volunteers, who poured in from many other areas, particularly the Atlantic and Gulf Coast areas of the United States . </P> <P> The 1867 yellow fever epidemic claimed many casualties in the southern counties of Texas, as well as in New Orleans . The deaths in Texas included Union Maj. Gen. Charles Griffin, Margaret Lea Houston (Mrs. Sam Houston), and at least two young physicians and their family members . </P> <P> The entire Mississippi River Valley from St. Louis south was affected, and tens of thousands fled the stricken cities of New Orleans, Vicksburg, and Memphis . An estimated 120,000 cases of yellow fever resulted in some 20,000 deaths . </P>

Why is there no yellow fever in the united states