"Hannah,

Two quickies from ""C & O Towpath"" google search:
http://www.bikewashington.org/canal/
This seems to be the definative site
http://www.nps.gov/choh/
this may be a supplement, or may not be helpful at all

You should check out Harper's Ferry W.Va, Only one building of the Federal Arsenal (re: John Brown's Raid, 1859) remains, but many Civil War era buildings remain; some of the movie Gods and Generals was shot here, (it stood in for Fredricksburg VA).

BUT, you can't start the towpath here, because Harper's Ferry lies in a slim peninsula between the Potomac and Shenendoah Rivers. Amtrak does stop in HF, as well as MARC, the regional (DC) rail authority. The rail line may parallel the towpath (rail on the south side of the Potomac in HF, must cross the Potomac downstream if it goes into Union Station. This could be an option entering or leaving DC with the bike.

The towpath starts in Cumberland, Maryland, so it seems to run on the north side of the Potomac. You probably have to detour into HF by way of US route 340.

But if you start in HF, you climb out of HF (a couple of hundred feet), then take 340 North over the potomac, then descend to the towpath. You are then 60 miles from DC on t

While you are in the vicinity of HF, you could go 15 miles north on a twisty, narrow pretty road to Sharpsburg Maryland, and tour Antietam National Battlefield. If you are there the thrid weekend of September (you'd be missing the ENY, but let's not quibble), you would be there on the 142nd anniversary of the battle (September 17-18, 1862). There could be a reinactment scheduled, you may wish to contact the National Park Service. I was there last week during the heat wave. In that heat, moving along the roads, it was easy to imagine the effort the soldiers had to make, either carrying a full 50 pounds for the march, or 15-20 pounds of muskets, ammunitions, and water for battle. What I could not imagine was doing this in full length clothing of cotton and wool.

questions contact me by email or 212 371 7906. Have a safe trip

"

You could also use the W&OD path that runs from Purcellville, VA to DC (Georgetown). It's not scenic (at least the parts I've ridden) but it's car-free and mostly flat the entire way through congested Northern Va. You'll have to cross some suburban roads, but there are overpasses that get you over major highways. The path goes through Leesburg, which has a quaint colonial downtown, though it's surrounded by suburbia.

My bike trip went off exactly as planned at the end of Labor Day weekend; I spent Mon.-Tues. riding from Middletown to DC.

Someone from a Potomac-area bike club made me a route to get to Middletown, VA, to Harpers Ferry, WV, on secondary roads through lots of small towns with good food options. Harpers Ferry has a large Civil War-era district that looked like it would be interesting to visit, but I headed straight to the bridge across the Potomac, which had a nasty metal spiral staircase to get to the C&O towpath. The trail was beautiful and full of life--human and otherwise--on Labor Day. Great blue heron, deer, and lots of Monarch and Swallowtail butterflies were among the highlights. Total mileage for the day was about 75 miles.

I camped in a free hiker-biker site right along the river about 30 miles outside DC and finished up the ride the next morning. My bike was barely tough enough for the unpaved, rocky trail, and I had a headache for a while afterward from all that jarring riding, so I probably wouldn't go the same way again, but even so I really enjoyed it.

The last few miles into DC were on pavement courtesy of the Capital Crescent Trail. Once in the city, I headed for the Mall where I dusted off my bike and ate breakfast. Then it was off to Chinatown for the blessed bus: $20 to NY in 4 hours without having to take anything off my bike.