I have never flown through MSP, so I cannot speak to the layout of their airport. But, back in '06, my family flew American Airlines from IND to MSY, with a 55 minute layover at ORD. We arrived at our gate and could see the plane, but the doors were closed and we watched our plane pull away (several minutes later). We dealt with many rude people before finally being booked on another flight more than 7 hours later. However, our luggage did make it onto our original flight. It was sitting in baggage claim waiting for us. Returning from MSY to IND we had a 45 minute layover at DFW. This time when we arrived at our gate, the attendant had tickets for the next flight in hand--as our flight had once again just closed the door. These are the only two flights I have ever missed.
From these experiences I learned that, if you are traveling with children, you should really have a layover of about 1 1/2 hours. That should be enough time to make it to your next gate, and even give the first flight a little bit of time to be late. If there is another flight option that gives you just a little bit more leeway in your layover time, I'd grab it.
Hope this helps,
JenIN