Do amended charges show up on background checks?

I was arrested in Missouri for Resisting arrest. I took a plea bargin deal and had the charge amended to littering because the prosecutor had a poor case. My question is I recently applied for a job at the post office and they do their background check with a company called General Information Services. I plead guilty to littering which is a municipal ordinance, but the resisting arrest charge is a cl A misdeameanor. In the application I listed I was never convicted of a felony or miseameanor (which would be the truth since a plead guilty to the lesser charge of littering). Will the littering charge show up on the background check or the original charge? I was also told most companies do thier background checks searching the State and county that you live in since I never lived in Missouri they might overlook the whole incident, but I figured the Federal Post office might conduct a better background check than most employers.