His colleagues on the paper were Charles Kickham and Thomas Clarke Luby, while John O'Leary was in charge of the editorial department.

Superintendent Daniel Ryan, head of G Division of the DMP, with this and additional information, raided the offices of the Irish People on 15 September and arrested the staff.

On 6 February 1877 Mulcahy discovered the former head of the American Fenian Brotherhood, John O'Mahony, dying in a New York garret and despite his best efforts, he was unable to save his life.

Mulcahy later lamented in a written piece for the Nation reporting upon the well-attended funeral that "we seem to set more value on the dead patriot's bones than on his living brains".

[1] Mulcahy opposed the "New Departure", a movement that sought to unite physical force Republicans with constitutionalists such as the Irish Parliamentary Party.

[1] Mulcahy spent the last years of life prospering; he ran a successful medical practice in Newark, New Jersey and it was there he died on 13 September 1900.