Robert Hunter was born in Terre Haute, Indiana, in 1874. After graduating from Indiana University he moved to Chicago and in 1896 was appointed organizing secretary of the city's Board of Charities. His work brought him into contact with Jane Addams and he became a resident of Hull House where she joined other social reformers such as Ellen Gates Starr, Edith Abbott, Grace Abbott, Mary McDowell, Florence Kelley, Julia Lathrop, Alice Hamilton and Sophonisba Breckinridge at the settlement.
Hunter returned to Chicago and served as chairman of the City Homes Association. He published Tenement Conditions in Chicago (1901) and the following year moved to New York where he became head of the University Settlement House. In 1903 Hunter married Caroline Stokes, the sister of the wealthy industrialist, J. G. Phelps Stokes (1872-1960).
In 1904 Hunter published his book Poverty. Based largely on his experiences in Chicago and New York, Hunter, who considered himself to be a sociologist, attempted: (i) "to define and measure poverty"; (ii) "to describe some of its evils"; (iii) "to point out certain remedial actions"; and (iv) "to show that the evils of poverty are procreative". Hunter argued in his book that there were over 10 million people living in poverty in America.
Hunter had his work published in a wide-variety of newspapers and journals. His books included Socialist at Work (1908), Violence and the Labor Movement (1914), Labor in Politics (1915), Why We Fail as Christians (1919), Inflation and Revolution (1934) and Revolution: Why, How, When?(1940). Robert Hunter died in Santa Barbara on 15th May, 1942.