"The Road Not Taken" was first published in 1915 in an American magazine called the Atlantic Monthly. The poem was also the first poem in Frost's 1916 collection of poetry, entitled Mountain Interval.

Many believe that the poem was inspired by Frost's friendship with an English poet named Edward Thomas. Thomas was thinking about joining the British army (mandatory conscription was not introduced in the UK until 1916) but couldn't make up his mind. He hated the jingoism with which the war was reported, but felt a duty nonetheless to fight alongside his fellow countrymen. In 1915, Frost sent Thomas the poem, then titled "Two Roads." Many people think that this poem was a factor in encouraging Thomas to enlist, as he eventually did in 1917.

In a more general sense, given that Frost wrote the poem in the early part of World War I, it can also be interpreted as a response to the decision of the US not to intervene. The president at the time, Woodrow Wilson, declared that America would stay "impartial in thought as well as in deed." America did not join the war until 1917. As an American citizen, Frost may very well have been reflecting, in "The Road Not Taken," on his country's non-interventionist stance.