I found a Serill Alger, son of Truman and Charlotte Alger in Freedom Township, Cattaraugus County, NY. Truman and Charlotte Alger moved to Olive Township, Clinton County, Iowa. This Serill Alger was born 1837-38 in Cattaraugus County, NY.
Truman Alger was born June 27, 1808 to Saral and Mary (Polly) (Jackson) Alger. Hope this helps.