When was "The Road Not Taken" published?

Robert Frost's "The Road Not Taken" was published in 1916. However, Frost probably wrote this poem a year or two years earlier, in 1914 or 1915, in the early years of the World War I. He wrote it during a period spent in England, when he met the Welsh writer Edward Thomas. The pair would often go walking together; the poem was meant as a humorous comment on Thomas's chronic indecisiveness—although neither Thomas, nor many other readers, interpreted it in this way. Frost sent the poem to Thomas directly and, when Thomas took it as a call to action, wrote back to explain the joke. Thomas replied that if Frost wanted the poem to be read as a joke, he had probably better point out to people where they should laugh.
Ultimately, Thomas enlisted in the British Army and was killed in World War I.

"The Road Not Taken" was published in 1916, in a volume of poetry called Mountain Interval. Although we tend to think of it as an American poem, it was actually written in England. According to Helen Smith in the book An Uncommon Reader, the poem arose from walks Frost took in the English countryside with British poet Edward Thomas. Thomas apparently would sometimes take a long time pondering which way they should go when they came to a crossroads while walking.
Although urged to go to the United States at the beginning of World War I, Thomas enlisted in the British army and was killed in the war.
Even though it is set in England rather than New England, the timeless quality and universal message of the poem seem to suggest that it could have been written in any number of places.

"The Road Not Taken" was published in 1916.