C&O canal bike path

Details? What kind of bike? How much load? Camping or not?

My immediate family did it with full camping loads on touring bikes after a very wet spring. It was bumpy and muddy and at times almost unridable. Our main issue was the sticky mud packed between tires and fenders, and needed to be scraped out repeatedly.  If it's been wet, fenders (if any) should have big clearance.

Another family member did it with minimal load on a hybrid bike, no fenders, and after a dry spell. They stayed in B&Bs, hostels, (IIRC) etc. and did well although they're less enthusiastic cyclists. Yet another family member did it on an old 1970s 10 speed with homemade panniers, homemade fenders etc. He did fine.

The trail is often very bumpy, with grass growing down the center. It is NOT a manicured bike path. Use wide tires (35mm at least) at lower pressures. And consider a different trip if it's been wet lately.