Sorry, I don't have time to verify this right now, but this should help you to get started on the process.
Alanson DUNHAM (18 Jan. 1814, Franklin, Delaware Co., NY - 1887) m. 20 Sep. 1849, Madison, Madison Co., NY, Adelia Ann BALLARD, b. Apr. 1828, NY.
Elijah Rodney DUNHAM (14 July 1783, Glastonbury, Hartford, CT - 1851) & Temperance CURTIS (1783 - 1851).
Levi DUNHAM (1745 - 1821) & Anna WADHAM / WADDAMS (1760 - 1844).
Isaac DUNHAM & Jerusha LOOMIS
Google this: "Isaac Dunham" +"Jerusha Loomis."
On the census of 1850, Owego, Tioga, NY, Elijah R. DUNHAM was 69 [sic] , & Temperance, 68 [sic]. His birth date and the names of his parents are verified by the Barbour Collection of CT Vital Records. The 1880 census says Alanson's parents were born in Connecticut.
Elijah & Temperance had Rodney, Angeline, Julius, Henry, Alanson, Asa, Dorman, Levi, Waddams, Sylman, & Albright [per Ancestry.com].
In 1900, Carlton, b. 1869; Lena, b. Feb. 1874 had DeWitt, b. Je. 1894; Clarence, b. Aug. 1895; & Cleon, b. Sep. 1896. Widowed mother Delia A., b. Apr. 1828. The three sons were all at home in 1910, but only the youngest was there in 1920.
California Death Index: Carlton DUNHAM (29 Jan. 1869, NY - 2 May 1959, Los Angeles, CA).
Clarence DUNHAM (20 Aug. 1895, NY - 1985, Rensselaer Co., NY) m. Mary Emily COTTRELL (20 Sep. 1897, NY - 14 Dec. 1972), dau/o Nathaniel COTTRELL & Ruth ELDRED.
This is not my Dunham line.