Ulysses S. Grant, who did not think highly of Butler's military skills, ordered him to attack in the direction of Petersburg from the east, destroying the rail links supplying Richmond and distracting Robert E. Lee, in conjunction with attacks Grant would make from the north. Although Petersburg at this time was lightly defended and Butler could have occupied it with little difficulty, he hesitated and allowed a greatly inferior Confederate force under General Pierre G.T. Beauregard to box up the Army of the James on the Bermuda Hundred Peninsula. As a result, the Army of Northern Virginia arrived and dug in around Petersburg, resulting in an eight-month siege of the city. However, it was his mismanagement of the expedition against Fort Fisher, North Carolina, that finally led to his recall by General Grant. Butler devised a scheme to sail a boat filled with gunpowder up to the fort and detonate it, breaching its defenses, after which infantry would land ashore and storm the place. The plan went completely awry when the boat exploded prematurely in the harbor outside Ft. Fisher, doing no damage whatsoever and was barely even noticed by the Confederate troops manning the fort. Butler landed his infantry ashore, then gave up, recalled them, and reported back that Ft. Fisher was impossible to capture. Afterwards, Admiral David Dixon Porter informed Grant that it could be taken easily if anyone competent were put in charge.