Yes, there is another pizza restaurant that claims to be the oldest in the USA. Yes, they opened in 1905, seven years before Papa's. BUT, THEY WERE CLOSED FOR TEN YEARS, then reopened, but owned by a different family, in a different location. Papa's has been owned by the same family since it opened, and has never closed for more than a week or so (after a fire.) Here are some links that confirm this history:
From the New York Times "Diner's Journal", July 2011:
From the "Newark Star Ledger" newspaper, by food writer Peter Genovese, July 2011:
From the "Times of Trenton" newspaper, August 2011:
From "Slice" pizza blog, February 2011 - scroll to the end for this quote about the pizza place that claims to be older than we are: "...... it's certainly not the oldest continuously operating one. That would be Papa's Tomato Pies in Trenton, New Jersey."
From National Public Radio (NPR), "All Things Considered", August 2011: