Turn-of-the-Century Peter, Joe, Quagmire & Horace are the respective ancestors of Horace, Peter Griffin, Joe Swanson and Glenn Quagmire that hang out at The Drunken Clam circa 1901 in "Save the Clam".
As with their modern-day counterparts, they are voiced by Seth MacFarlane, John G. Brennan and Patrick Warburton.