"We are the Fenian Brotherhood, skilled in the arts of war,
And we're going to fight for Ireland, the land we adore,
Many battles we have won, along with the boys in blue,
And we'll go and capture Canada, for we've nothing else to do."
-Fenian soldier's song
Éirí Amach na bhFiann (Fenian Revolution) was successful, and New Erin (formerly New Brunswick) was established in 1870. It has since become an U.S. protectorate but still retains the autonomy of an independent country.
The Canadian border still sees some skirmishes between the army of New Erin and the British but England is losing interest as it's turning it's eye towards Mars.
I'm ruminating about what their uniforms should look like. I think that I'm just going to use U.S. Military style uniforms only with green hat's and jackets, and black pants- just some thoughts.