I would not have finished the project (in two years) without his help, we hired him after a year, too.
First thought: your manager was a tool, and generally a waste of space--actually he wasn't even THAT useful, since he actively made things worse overall.
That said... the above quote is a bit damning. You claimed you needed two additional people, an empty task list, and two years. You did the job in two years, with other tasks encroaching on your time, and with a single new grad that you only had for 21 of those months. Either your project was a death march (not ruling that out, mind you), or your estimate was woefully off--maybe to the point that the dipshit manager, if you two had a history, simply didn't trust your ability to give him a good answer and modified it per past performance.
I'm sure there were many more factors in play than you mentioned above, which probably invalidate what I'm saying, but it might be worth taking a step back here and asking yourself if you made any mistakes you could learn from (other than working for Mr Clueless, of course).