I've applied for US B1/B2 Visa and scheduled an interview. I have to attend a 4-day conference but I have entered the length of stay in the US as 10 days in the DS-160 form. This is because my conference is in Nashville and my port of entry in the US is New York City.
Now, I can take another flight between Nashville and New York, but I've decided to travel by bus (since this will be my first visit to the US and I really want to explore it by land). The round-trip time via bus is 2 overnight trips, and this adds to the total number of days to stay. To be clearer, following is my rough schedule:
24th evening - arrival in NYC
25th - recover from jet lag (travelling from India) and hopefully some sightseeing
26th - overnight bus trip to Nashville
27th - arrival in Nashville
28th to 31st - conference
1st - overnight bus trip back to NYC
2nd - arrival in NYC and flight back to India
Now, if the consular officer asks me about my purpose of visit, should I just say "attending a conference", or "attending a conference + sightseeing". Also, if s/he asks me why I'd be staying for 10 days, I want to genuinely answer that "I want to do some sightseeing as well" (and go through my above schedule if needed), but is this a "good enough reason"? I don't want my visa to be rejected on the grounds of "unclear purpose of travel".