It's a bit ironic that this particular song should be the topic of a copyright dispute, especially since Woodie Guthrie put this as a copyright notice on one of his songs:
This song is Copyrighted in U.S., under Seal of Copyright # 154085, for a period of 28 years, and anybody caught singin it without our permission, will be mighty good friends of ourn, cause we don’t give a dern. Publish it. Write it. Sing it. Swing to it. Yodel it. We wrote it, that’s all we wanted to do
And also since these lyrics are part of the song:
Was a high wall there that tried to stop me
A sign was painted said: Private Property,
But on the back side it didn’t say nothing –
This land was made for you and me.
LINK:
https://www.techdirt.com/articles/20160626/02151034825/this-song-belongs-to-you-me-lawsuit-filed-to-declare-woodie-guthries-classic-public-domain.shtml