On return to Ireland Martin became a national organiser for the Tenant Right League. He began to write for "The Nation" in 1860. He formed the National League with others in January 1864 – it was mainly an educational organisation but Fenians disrupted its meetings. He remained in contact with Mitchel in Paris through 1866. Martin opposed the Fenians' support of armed violence, yet, together with A M Sullivan, in December 1867 he headed the symbolic funeral march honouring the Manchester Martyrs as it followed the MacManus route to Glasnevin Cemetery, Dublin. He was briefly arrested for these activities but the charges were dropped.