 Founded and initiated at Westport, County Mayo by William O'Brien, it was supported by Michael Davitt MP, John Dillon MP, who worded its constitution, Timothy Harrington MP, John O'Connor Power MP and the Catholic clergy of the district.By 1900 it had expanded to be represented by 462 branches in twenty-five counties.In 1895 William O'Brien retired from Parliament and the Irish Parliamentary Party (IPP) in the wake of the Parnell split, by which the party became fragmented into three separate networks of local organisation—the Parnellite Irish National League, the Dillionite anti-Parnellite Irish National Federation and the Healyite Peoples Right's Association.