The timing of the adoptions of maize and squash across eastern North America has been a topic of long-standing interest among archaeologists and paleoethnobotanists. The use of flotation for macrobotanical remains beginning in the 1960s and 1970s coupled with the application of accelerator mass spectrometry dating beginning in the 1980s has led to substantial revisions of knowledge about the history of these crops in the region. A complementary source of evidence for the crops histories in the eastern North America comes from opal phytoliths. Analysis of phytolith assemblages recovered from charred food residues has shown that maize and squash were being used in central New York well before the macrobotanical record indicates. In combination with previously analyzed samples, 16 additional residue assemblages help to clarify the history of maize and squash in central New York. The results indicate that maize and squash were being used in New York by 2270 B.P and 2945 B.P, respectively.