Some 10,000 alien plants and animals live in North America. Our lawns sprout African grasses, our roadsides flower with European weeds, and our homes harbor Asian, European, and African pests. The iconic American cowboy spread such alien life forms as cows, horses, anthrax, and tumbleweed, supplementing the often unexpected ways ""Native"" Americans influenced the environment. Misguided enthusiasts deliberately introduced carp, kudzu, and starlings. Leland considers the new home that these ""aliens in the backyard"" have made for themselves on the continent, but he employs an approach different from that of most naturalists. While environmentalists almost universally decry the invasion of non-native species, Leland finds that uncovering their stories of arrival and assimilation to be the more intriguing endeavor. Leland does mourn such ravages as the chestnut blight, Dutch elm disease, and gypsy moth, but he discovers that the vast majority of alien plants and animals, like their human counterparts, go about the business of existence and reproduction without threatening anyone or anything. In a volume that is part natural history, part anecdote, and part ode to survival, Leland cuts through myths coloring our grasp of the natural world and suggests that the stories of how these plants and animals have reshaped our landscape are as much a part of the continent's history as that of our presidents and politics. At the same time Leland poses questions about what exactly, of all our accepted icons, is truly American. Not apple pie or Kentucky bluegrass; not Idaho potatoes or Boston ivy. With an engaging style and genuine appreciation for nature's resiliency, Leland forces us to rethink our understanding of what it means to be American. He reveals how plant and animal invaders have made the country as much an environmental melting pot as it is melding of peoples and cultures.