1. House Sparrow (Passer domesticus), first introduced by the New York-based American Acclimatization Society in the 1850s, and by others during that decade.

2. Starling (Sturnus vulgari), first introduced by Eugene Schieffelin of the American Acclimatization Society into Central Park in 1877.

3. Rock Pigeon (Columba livia), first introduced to North America in 1606 at Port Royal, Nova Scotia.

4. Kudzu (Pueraria lobata), first introduced on a large scale to America from about 1935 by the Soil Conservation Service and the Civilian Conservation Corps, which planted it extensively in southern states in an effort to control soil erosion.

5. Dandelion (Taraxacum officinale), first introduced by British colonists as a garden green and medicinal herb.

6. Common Carp (Cyprinus carpio), first brought to the U.S. in 1831, but widely introduced by U.S. Fish and Fisheries Commission head Spencer Fullerton Baird soon after 1871, as a food source in the nation's overfished rivers and lakes.

7. Water Hyacinth (Eichhornia crassipes), first introduced into North America in 1884. It now clogs many lakes, ponds, and inland waterways.

8. Gypsy Moth (Lymantria dispar), introduced to Medford, MA, in 1868, by French amateur entomologist Étienne Léopold Trouvelot, in an effort to cross breed them with silk moths in the U.S., which had become susceptible to various diseases.