Orient’s extra-time victory over Oldham began a run of 15 wins in 20 matches in all competitions, including their victory over the Rams on penalties.
Had it not been for a blip of five straight defeats at the end of February and beginning of March, the O’s play-off place could have been sealed well before the final day of the season away at Huddersfield Town.
“We’ve all said it, the gaffer’s said it, even when we were going through that rough stage we had the players, we had the belief we could turn it around,” Galbraith said.
“I’m not to sure too many people thought we could, but I think inside the group we knew we could go on to better things.”
The O’s have been boosted by the return of Jack Currie for the final. The defender was substituted after picking up an injury in the second leg at Stockport.
Club captain Omar Beckles described his team’s resurgence in the second half of the season as a “miracle”.
“In December we were in the relegation zone. To have turned things around in the way that we have has been nothing short of a miracle, to be on the cusp of getting into the Championship,” he said.
“Extremely excited. Really looking forward to the occasion and to hopefully go and make history.”