Did Sean Mac Fheorais write a poem about the red coats called Anseo you Lar an ghleanna?

The poem "Anseo you Lar an ghleanna" was not written by Sean Mac Fheorais. It is a traditional Irish folk song, also known as "The Boys of the Glen". The lyrics of the song can be traced back to the 18th century, and the song has been recorded by numerous folk artists, including The Dubliners and The Clancy Brothers.