Cramer, Jefrey S., Robert Frost Among His Poems, Jefferson, NC: McFarland & Co. Inc., 1996.

Cramer gives a brief but thorough background of almost every poem Frost has written. An indispensable guide.

Johnson, Paul, Modern Times: The World from the Twenties to the Eighties. New York: Harper and Row Publishers, 1983.

Not as fun or interesting to read as Geoffrey Perrett's book listed below, but full of more factual information.

Perrett, Geoffrey, Americans in the Twenties, New York: Touchstone Books, 1983.

This book is filled with fascinating anecdotes that bring the decade alive. All aspects of life are covered.

Suchard, Alan, et. al., Modern American Poetry, 1865-1950, Boston: Twayne Publishers, 1989.

The author paints a portrait of Frost as a bitter and brilliant man, quite the opposite of the impression one gets of him from his poetry.