Hardshells & "Calvinism"

Today's Hardshells frequently decry "Calvinism," as well as "Arminianism," and find it necessary to say to people "we are not Calvinists." Yet, I find in reading the writings of the PBs in their first fifty years or so (1830-1880) how those PB forefathers often called themselves Calvinists. So, what happened to change things in this regard? Could it be that the date when they cast off a belief in means is also the date when they began to denounce "Calvinism"?