I used to make a daily commute from downtown Richmond to Crystal City, 90 minutes is possible on Sunday mornings before 10am All other times, plan for 2-1/2 hours.
Traffic through Fredricksburg and crossing the Occaquon on a Saturday is routinely a killer, and that's northbound, southbound, even late after a game would likely be pretty heavy.
There was a time you could've seen some pretty good AAA ball in Richmond, but the Braves pulled out last year.
The Potomac Nationals might be playing that weekend, that'd save you about an hour drive time each way...