My preferred route would be I-80 to I-74.
Near Indianapolis I-74 dumps you onto the construction on I-465 on the west side of Indy.
TO AVOID THAT: In Indiana take Exit 39 (SR 32) to I-65 - a real nice relaxing drive through farm country on a fine 2-lane road.
South 10 miles on I-65 to I-865E, then I-465 East to I-70.
There has been some work being done on I-65 but no real problems.
I-70 through Columbus is not too bad - it is well marked - or take I-270.
I-470 around Wheeling, WV.
I-70 to the PA Turnpike (I-70).
Follow that to wherever you want to go in MD.
I have used this route many, many times in our travels from PA westward and eastbound
If you use them, FJ/Pilot stations are nicely spaced along this route.
Some campgrounds we use:
East Galesburg, IL - I-74 Exit 54 Best Holiday Trav-L-Park
Mahomet, IL - I74 Exit 174 Tin Cup RV Park
Zanesville, OH - I-70 Exit 155 Wolfies Family Camping
Safe travels to you!
'14 Winnebago Vista 35F, '14 GMC Terrain
BlueOx Towing Pkg, SMI Stay-n-Play
49 States & 7 Provinces visited in MH | WIT W112365