The only Clifford E. ALSDORF born 1915-1919 in NY that I can find is this one on the 1930 census for Plattekill, Ulster, NY: ALSDORF, Charles age 56 b. NY, both parents b. NY wife Grace age 49 b. NY, both parents b. NY dau Mabel E. age 26 son Clifford E. age 13 son Ernest age 9 boarder REYNOLDS, James P. age 47 b. NY
In 1920 the family was in the same county and the children at that time were:Hezekiah, 18, Edith, 13, Mabel, 16, Alberta, 10, Charles, 9, Clifford, 3y3m, and Idella, 1y11m.
In 1910 they were in Gardiner, Ulster, NY.Oldest child was Lillian A, age 10
Same location in 1900.Charles was b. Dec 1874, Grace Feb 1881 and Lillie Dec 1899.
In 1880 in Gardiner, Ulster NY there's this family which is likely Charles and his parents: ALLSDORF, Laurence age 50 b. NY both parents b. NY wife Elizabeth age 52 b. NY, both parents b. NY son Charles age 6 b. NY