Truman was born circa 1800 somewhere in New York, believed to be Rensselaer County or Yates. I've been looking for his parents for a while, and my great uncle as been looking for years. Anyone know of good sources to search for these areas that I may be missing?
Christina: On the familysearch.org profile for Truman (but not the Wikitree profile) you have also already linked his 1840 census record from Potter Township in Yates County, NY. If you in addition want to link the NY state census records, here (12th from bottom) he is in 1845 in Potter Township, and here (2nd from top) he is in 1835. Before 1832 this area was still part of Middlesex Township, but there is no record of a Merritt in Middlesex Township in either the 1830 federal or the 1825 NY census.
I have checked both the grantor and the grantee indexes for Yates County deeds; there is no evidence that Truman ever bought or sold land there (he did farm, as evidenced by the 1835 census, but must have been a tenant farmer).