Mr McLoughlin, who is the Conservative MP for Derbyshire Dales, was addressing the Derby and Derbyshire Rail Forum.
He said the new high speed rail line will cut journey times between the Midlands and London and the North, but the main advantage would be in tackling overcrowding on our trains.
The Secretary of State also defended the choice of Toton for the site of a new HS2 station serving the East Midlands. He said it would serve the region well.
On franchising, he admitted his department had made "some very serious mistakes" over the West Coast mainline contract. But he said he had taken action to put things right.
He also announced his intention to prove Sunday rail services, after revealing he regularly travels by train on Sundays.