STEAMBOAT ACCIDENTS.--The steamboat United States which left Buffalo on Friday evening for the Upper Lakes, struck upon a rock in a fog on Saturday morning, about four miles above Portland Harbor, and sunk in about eight feet water. The passengers, an unusually large number of whom were on board, the crew and the cargo, were with some difficulty safely landed on the beach. By the unwearied exertion of capt. Hart, and his crew, she has since been raised, and, on Tuesday evening, arrived in Buffalo in tow of the North America. She will be able to resume her trips in about ten days.

The steamboat William Penn went on shore the same morning a few miles below Erie, but fortunately got of the same day without material damage.