Waskow was born in Baltimore, Maryland. He received a bachelor's degree from The Johns Hopkins University in 1954 and a Ph.D. in American history from University of Wisconsin–Madison. He worked from 1959 to 1961 as legislative assistant to Congressman Robert Kastenmeier of Wisconsin. He was a senior fellow at the Peace Research Institute from 1961 through 1963. He joined Richard Barnet and Marcus Raskin and helped to found the Institute for Policy Studies in 1963, and he served as resident fellow until 1977.