Poliomyelitis, often called polio, is a highly infectious viral disease which mainly affects young children. The virus is transmitted through contaminated food and water and multiplies in the intestine where it can invade the central nervous system causing paralysis and/or difficulty breathing. Despite intensive efforts to eradicate the virus through polio eradication programs, polio remains endemic in Afghanistan, India, Nigeria, and Pakistan. This book concerns a deterministic model of the spread of polio built upon two epidemiological age groups. Discussed within this book is the the structure of the model, equilibria, classification of equilibria, and stability analysis. Lastly, the model is applied to the United States polio outbreak during 1952 to confirm that the model is biologically relevant.