Once they got to the ground, however, they saw exactly why their team was slipping out of the football league after 35 years.
United missed good early chances as County struggled to settle into a windswept game, and they could have gone in at the break three or four goals down.
County's Mark Stallard and Steve Scoffham sliced through a threadbare defence forcing a string of saves from young goalkeeper John Ruddy, who earned his man-of-the-match award.
But Ruddy was relieved to see Scottham's 25th minute effort bounce off the crossbar, and a couple of minutes before the break Stallard's shot was cleared off the goal-line by defender Tom Newey.
United skipper Andrew Duncan, who collected the supporters' player-of-the-season award before the start, had a header blocked on the goal-line by Matthew Gill in only the second minute.
But there was an hour on the clock before the next real threat from United. County keeper Saul Deeney had to fingertip a lobbed shot from Darren Quinton over the crossbar.
There might have been a farewell goal from Cambridge, but Danny Webb's shot in the 73rd minute was blocked on the line by Deeney.