Robert A. Heinlein (1907-1988) is generally considered the greatest American SF writer of the 20th century. A famous and bestselling author in later life, he started as a navy man and graduate of Annapolis who was forced to retire because of tuberculosis.  A socialist politician in the 1930s, he became one of the sources of Libertarian politics in the USA in his later years. His most famous works include the Future History series (stories and novels collected in The Past Through Tomorrow and continued in later novels), Starship Troopers, Stranger in a Strange Land, and The Moon is a Harsh Mistress. Given his desire for privacy in the later decades of his life, he was both stranger and more interesting than one could ever have known. This is the first of two volumes of a major American biography. This volume is about Robert A. Heinlein's life up to the end of the 1940s and the mid-life crisis that changed him forever.