The most authentic information on the introduction of the water hyacinth into Florida indicates that a visitor returning from the Cotton States Exposition in New Orleans in 1884 brought with him several of the plants. Perhaps because of the showy lavender flower, the plants were placed in a lawn fountain on the banks of the St. Johns River near Palatka, Florida. As the plants rapidly multiplied and filled the pond, excess plants were discarded into the St. Johns River. By 1896 the plants had spread throughout most of the basin, and by 1898 the plant population had increased to the point that steamboats and other vessels were unable to reach docks or pass through navigation openings in bridges or narrow points in the river. Another major exotic plant pest, alligator weed, was introduced into the U. S. from South America in the late 1800s.
Alligator weed is thought to have been introduced by way of ballast dumped from sailing ships.
This report resulted in the initial authorization for the control of waterhyacinth in federal navigation projects under Chapter 425, Section 1, River and Harbor Act of 1899. This act authorized the construction and operation of vessels and log booms for the removal and containment of water hyacinth in navigable waters of Florida and Louisiana. These methods did not prove adequate to manage the problem. In 1902 Congress authorized the extermination and removal of water hyacinths by any mechanical, chemical, or other means. Various materials were tested including muriatic acid, sulfuric acid, carbolic acid, kerosene, steam, sodium arsenite, mercury bichloride, whale oil soap, formaldehyde, copper sulfate, potassium bichromate, and many others.