Built in 1876 by W. W. Upp, the bridge crossed the Conestoga River[?] before it was swept away in Hurricane Agnes[?] and moved to its present location.
... square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...