US Post Office is located at 147 Quigley Blvd, New Castle, DE. This business specializes in Post Offices. US Post Office is open Mon, 8am-7pm; Tue, 8am-7pm; Wed, 8am-7pm; Thu, 8am-7pm; Fri, 8am-7pm; Sat, 8am-4pm; Sun, Closed and accepts American Express, Discover, Mastercard and Visa.