(wake me when this is over)

That is an impressive question. Off the beaten path for sure.

Petersburg, in general, was a poorly managed campaign on the Union side for 90% of its duration. Butler was always more politician than general and he was also the victim of some bad luck. In early June 1864, he (and Grant) felt he could take Petersburg and tried to with a small force (combined infantry and cavalry) which was still probably sufficient at the time. This would allow him to keep the main truck of the Army of the James in contact with the fleet near Bermuda Hundred, which as Ted notes, was a major chess piece to be defended. This maneuver was thwarted however, when the cavalry (under Kreutz? Krause? Some German name) got bogged down as they tried to circle in from the rear and that stalled the whole attack, alerting the Confederates of their vulnerability. The subsequent attack, about a week later with a much larger force, failed more because of Baldy Smith, XII Corps commander, then Butler (but Butler being unpopular and Smith's CO, got the blame). No less than Hancock ("The Superb") failed to seize the day, agreeing with Smith that they should wait for clearer orders from Grant even though the Union advantage was probably obvious, and that allowed Beauregard to reinforce his multiple defensive lines and dig in. Of course, Ted probably knows the rest - namely that everything devolved into an extended messy siege, the tactics of which foreshadowed WWI.

There are lots of opinions about Butler and, like many of the political generals, there is much to criticize. But, in general, the Petersburg thing was low on the list - more reputation than his actual failures in that case, at least. One other point about political generals, much of the "history" that comes down to us is filtered through political opinions, debates and campaigns. Fake news isn't a new phenomenon. Grant's memoirs, universally regarded for their accuracy, are generally kind to Butler.