Can someone travel to the USA if they have previously entered into a peace bond?

My husband is a permanent resident in Canada. He carries a british pport. We want to travel to the united states but we are worried he may not be permitted across the border. About 4 years ago he entered into a peace bond as a result of ault allegation. It is my understand that a peace bond is not a conviction. We had a criminal record check done and it came back clear but in the position of trust portion it does list that the matter was dealt with in court and dropped. Does anyone know if this would prevent him from crossing over? or who we could contact to find this out?