Billy Sharp opened the scoring, his third successive goal, and second half goals by Conor Sammon and David Edgar helped secure the points.
Gary Liddle pulled one back for the Bantams late in the game but the match was won in a terrific second half showing during which United produced some excellent football.
James said: "There was a period in the second half when Sheffield United played probably their best football under Nigel Adkins reign."
He added: "What that game against Bradford City showed is that you can do the basics, you can defend and be resolute but you can also score goals."
Watch the video to see James Shield's take on the game