For obvious reasons, when I go to book flights from BWI-BOS, I come across connections in PHL and LGA. However, in a few weeks, I would like to meet someone who is terrified of flying in CLT for the segment to BOS. If I called US for this, would they be able to make that my itinerary, or must I do multi city booking (and therefore pay a higher fare)?
You can get US to book this if you call in but you'll probably have to pay the $25 phone reservations fee. It helps if you have your flight numbers researched in advance as this routing doesn't usually come up on their reservation system. Not sure if multi-city fares will be cost-prohibitive but those do give you more control over how long you wish to stay in CLT; you might have a significantly higher fare connecting through CLT regardless of how you book it. I had a similar routing change made a couple weeks ago to avoid snowstorms that were due to hit NYC so we wanted to avoid LGA; the agent appreciated me having the flight numbers already in hand. You might also have luck with a third-party site; some let you choose your connection city in the filters once you've run your initial search.