This tidbit was found in a typed manuscript called "Early marriages from newspapers published in central New York; v. 01" on FamilySearch. On page 112, the following Leonard marriages are recorded:
Alfred Leonard, Jr. of Clay, and Sarah Bruce, of Clay. At Oswego, Aug. 8, 1846. Onondaga Democrat.
Ann S. Leonard (See Asa Barnes) On page 11, Asa Barnes entry reads as follows: "Barnes, Asa, of Wisconsin, late of Pompey, and Ann S., daughter of David H. Leonard, of De Witt. At De Witt (Mar. 3), 1847. (Onondaga Democrat)".
David H. Leonard (See Asa Barnes) ^
David Leonard and Joanna Hannum. June 14, 1838. St. James Church Record, Skaneateles.
Ezra Leonard and Mrs. Sarah Adams. At Skaneateles, Feb. 2, 1848.
Hiram J. Leonard. (See top of p. 113). "Leonard, Hiram J., of Lafayette, and Sarah C. Lamson, of Arcadia. At Arcadia, (Sept. 22) 1847. (Onon. Democrat)."
Jarvis Leonard of Vienna, and Polly Bishop, of Verona. At Verona, April 23, 1820. Onondaga Register.
Jennette Leonard. (See George S. Hall) On page 82, George Hall's entry reads as follows: "Hall, George S. and Jennette Leonard. At Auburn, (Feb. 23) 1831. (Onondaga Register)".
Samuel Leonard and Maria Austin. At Skaneateles, Nov. 24, 1819. Onondaga Register.
You can browse this book, free online at http://www.familysearch.org/library/books/idurl/1/529564
Creator: Beauchamp, William Martin, 1830-1925 and Lodder, Grace Beauchamp
Onondaga County once encompassed much of central New York. See the Formation of New York Counties.