New York Mystery

I was fortunate enough to obtain a box of 1897 Main family glass plate negatives from the US in 2012 and thought I should now scan and post the images. The relatively easy bit was finding out about the three graves in the first image. Thomas T Main (centre) died 12 Jan 1836 aged 81 years. He was born in 1755 and married Polly (left) in Willington, Tolland Connecticut in 1796. Polly was born in North Stonington, New London in 1774 and died 28 Dec 1837 aged 64.  The third stone (right) is for Sylvia Butcher. Find-A-Grave has modern day images for the grave. Polly's lies flat on the ground, while Thomas' is broken in half. They are listed as being in Root Cemetery but an additional image shows a sign bearing the words 'Cook Cemetery'. Polly is listed as having died in Clarendon, Orleans County, New York. The second photograph shows the grave of a George J Killian who died 3 Feb 1898. Find-A-Grave indicates he is buried in Oak Hill Cemetery, Owosso, Shiawassee County, Michigan. The memorial shown on F-A-G is different to that shown here. I cannot find a connection between him and the Main family. The other photos show a coffin and I presume the widow, along with some shots of what might be the family mill?