He then became the law partner of Isaac V. Vanderpool, and in 1869 became a member of the firm of Lanning, Cleveland & Folsom.  He continued a successful practice till 1870, when he was elected sheriff of Erie County.  At the expiration of his three years’ term he formed a law partnership with his personal friend and political antagonist, Lyman K. Bass, the firm being Bass, Cleveland & Bissell, and, after the forced retirement, from failing health, of Mr. Bass, Cleveland & Bissell.  In 1881 he was nominated the Democratic candidate for mayor of Buffalo, and was elected by a majority of 3,530, the largest ever given to a candidate in that city.  In the same election the Republican State ticket was carried in Buffalo by an average majority of over 1,600.  He entered upon the office January 1, 1882, and soon became known as the “Veto Mayor,” using that prerogative fearlessly in checking unwise, illegal, and extravagant expenditures.  By his vetoes he saved the city nearly $1,000,000 in the first half year of his administration.  He opposed giving $500 of the taxpayers’ money to the Firemen’s Benevolent Society on the ground that such appropriation was not permissible under the terms of the State constitution and the charter of the city.  He vetoed a resolution diverting $500 from the Fourth of July appropriations to the observance of Decoration Day for the same reason, and immediately subscribed one-tenth of the sum wanted for the purpose.  His administration of the office won tributes to his integrity and ability from the press and the people irrespective of party.  On the second day of the Democratic State convention at Syracuse, September 22, 1882, on the third ballot, was nominated for governor in opposition to the Republican candidate, Charles J. Folger, then Secretary of the United States Treasury.  He had the united support of his own party, while the Republicans were not united on his opponent, and at the election in November he received a plurality over Mr. Folger of 192,854.  His State administration was only an expansion of the fundamental principles that controlled his official action while mayor of Buffalo.  In a letter written to his brother on the day of his election he announced a policy he intended to adopt, and afterwards carried out, “that is, to make the matter a business engagement between the people of the State and myself, in which the obligation on my side is to perform the duties assigned me with an eye single to the interest of my employers.”  The Democratic national convention met at Chicago July 8, 1884.  On July 11 he was nominated as their candidate for President.  The Republicans made James G. Blaine their candidate, while Benjamin F. Butler, of Massachusetts, was the Labor and Greenback candidate, and John P. St. John, of Kansas, was the Prohibition candidate.  At the election, November 4, Mr. Cleveland received 219 and Mr. Blaine 182 electoral votes.  He was unanimously renominated for the Presidency by the national Democratic