He estimated that Belford Brothers' edition of The Adventures of Tom Sawyer alone had cost him ten thousand dollars (equivalent to $290,000 in 2020).[62] He had unsuccessfully attempted to secure the rights for The Prince and the Pauper in 1881, in conjunction with his Montreal trip.[62] Eventually, he received legal advice to register a copyright in Canada (for both Canada and Britain) prior to publishing in the United States, which would restrain the Canadian publishers from printing a version when the American edition was published.[62][64] There was a requirement that a copyright be registered to a Canadian resident; he addressed this by his short visits to the country.[62][64]