What do you make of this crack in foundation

[Tyler Weiss]

Would a diagonal crack in the foundation worry you? House build in 76 in clay soil in st louis, Mo. The basement has cracks in 3 of the 4 walls.  My goal is hold this property for the long term.  Could be a simple fix or major problems for the long run. 

[Jared Baker]

I've seen this in Wisconsin, results for poor construction practices.  Foundations should never be backfilled with clay due to the moisture retention.  As a result when the ground freezes, the clay will expand pushing on the wall.  If the wall isn't bowed in you can take a precautionary action and brace the wall.  If it is, you'll need a foundation specialist to come and push the wall back and install the bracing.  Other option of course is if it is not bowed to leave it.