Tough call without a State listed for Parkersburg and nine located in the US. One each in:
The closest one should be in West Virginia at 164.03 miles. If what you are seeking is a pleasant two week, round trip, auto tour you should consider Parkersburg Oregon which is 2,747.24 and crosses through:
For a change of scenery consider making the return trip via El Paso Texas for example which isn't directly as you requested but at 3,503.69miles it would surely add some spice to the trip and allow you to tour some extra states like:
Total mileage 6,250.93 miles and only about 446.5 a day for two weeks. It sounds like an excellent plan.