Recent historical data for flights between two airports

Hi, I’m new to this site and am trying to obtain historical data on flights between two airports (BWI and EWR) on a specific carrier (United) for two specific days (April 3 and 4).

Our family had a flight that was diverted then cancelled and purchased train tickets to get home; in order to receive reimbursement we need to show the insurance company that there were not other available flights in a “reasonable amount of time”. Since the airline can’t help us, I’m hoping to find data here, but can’t figure out the way to search without trying to sift through every single flight that left BWI for the past month. Surely there’s got to be a filter method I’m not seeing, and I’m hoping someone is kind enough to help me understand it. Thank you!