Guthrie originally wrote and sang anti-war songs with the Almanac Singers, but after America's entry into World War II he began writing anti-fascist tunes. Guthrie famously wrote the slogan "This Machine KillsFascists" on his guitar. He joined the U.S. Merchant Marine, where he served with fellow folk singer Cisco Houston, and then the U.S. Army.

　　In 1944, Guthrie met Moses "Moe" Asch of Folkways Records, for whom he first recorded "This Land Is Your Land," along with hundreds of other songs over the next few years.