Cemetery Establishment:

I went to see Hancock with my cousins, and on my way, I saw a stone sign. It read "Bostwick Cemetery Established 1859". Now, I'm not an expert on such things, but does that mean that this is when someone first died? If that's not the case, is there some sort of cemetery land permit that has to be designated? So does that mean people would be buried before the sign? What does it mean?!