"Iron Horses: American Locomotives 1829-1900" by E. P. Alexander is a book published in 1941 that focuses on the history of American locomotives during the 19th century. The book delves into the development of railway transportation in North America, specifically in the United States, and provides detailed insights into the evolution of locomotives during this period. With a theme centered around railwayana, this book is a valuable resource for those interested in the history and legacy of American locomotives.