William James was born at the Astor House in New York City, United States on January 11, 1842. He was the eldest born in the family of intellectuals and had four siblings. His father Henry James Sr. was a philosopher and his mother was Mary Walsh James. His younger brother Henry James became a great author while his other two brothers Wilky and Bob joined the Union Army. They were a wealthy family and spent time between America and Europe.
His father also was a man of unusual intellectual and literary ability, who had he been born a generation later would in all probability have taken a prominent place among America's outstanding cultural pioneers. William James, the son, enjoyed in this respect the good luck denied his father.