I am trying to determine the dates that my 4th great grandparents passed away.

Joel Graves Porter and Cordelia (Armstrong) Porter were married in Vermont in 1826. By 1840 they were living in Newfane NY.

The last record I can find for them is the 1880 census, where they are both living on their son George's farm in Newfane. Joel was 76 and Cordelia was 72. Neither of them are in the 1900 census.

Since the 1890 census is gone, that leaves a possible twenty year span where they could have passed.

Can anyone help me out?

Thanks,

Mark Martin