Are you driving? Do you have 10 days to go round-trip?

Are you interested in cities/small towns/natural environment? Great restaurants? Shopping? Hiking? Museums?

Give us a little more information.

How many people is a huge group? If the 10 days includes all of the travel time, you will not have very much time to enjoy all of the places. Just the logistics of moving a large group around is time-prohibitive. I would probably suggest picking 1 of them and staying there. DC is the closest to Atlanta and is still a long drive (around 12 hours - 600 miles).

The only way this trip makes sense is to fly into Buffalo, spend 2 nights in Niagara Falls (Canadian side - you will need your passports), then fly to NYC, spend several days there and then take Amtrak to DC - and finally either fly or train to Atlanta. (Based on your post I assume English is not your first language and don;t know your nationality. If you hold foreign passports you need to determine if you are allowed to enter Canada and then reenter the US.)

If you try to do this by car you will spend almost all of your time on the road and have time to actually see very little.

In New York I think you want to see fireworks - not firecrackers.

This takes place in the harbor - not sure if the Hudson or East river this year - but you can google it. It will be at 9 pm on the night of July 4th. Be aware that the weather is usually very hot and humid and there will be upwards of a million people lining the shore to watch the fireworks. All public transit in and out of the area stops at least 5 hours in advance - so you will have to walk in and out. Bring plenty of water to stay hydrated - but be aware that public toilets are not provided.

For recommendations on hotels you need to provide budgets and tell us how many people you are and how many rooms you will need. This is;t high season n NYC - but prices won;t be rock bottom either. You should be looking now - as in today - to try to find a decent place at a discount.

16 Hours Atlanta to Niagara Falls (add 4 hours for restroom and multiple meal stops). Halfway points include Cincinnati and Columbus OH - neither is compelling. Nonetheless, I would stop SOMEWHERE on route overnight to break up the drive.

8 hours Niagara falls to NYC (add 2 hours for restroom and meal stop)

5 hours NYC to DC (add 1 hour if stopping)

12 hours Washington DC to Atlanta (add 2-3 hours for stops)

All the above assume no traffic jams, which are likely.

If you still think this is a good idea:

Day 1 - Drive, stay somewhere midway between Atlanta and Niagara Falls

Day 2 - Continue drive to Niagara Falls (the Canada side, I hope. You've driven this far already, it would be a shame not to see the prettier side). Check into Niagara Falls hotel. Crash.

Day 3 - Explore Niagara Falls area for one day. Return to Niagara Falls hotel.

Day 4 - Get an early start on your drive to NYC. Check into NYC hotel after 8 pm. Crash.

Day 5 - Explore NYC

Day 6 - Explore NYC

Day 7 - Check out of NYC hotel stop for lunch somewhere in NJ outside of city. Continue drive to DC, check into DC hotel about 8 pm. Rest.

Day 8 - Explore DC

Day 9 - Explore DC

Day 10 - Check out of DC hotel at crack of dawn, and begin the long slug to Atlanta. arrive Atlanta about 11 pm - midnight.

Hopefully, everyone won't have to work the next day.

My only advice is to make sure that you are not crossing the border to Niagara Falls Canada on 4th of July weekend. The traffic backups can be brutal. If you can, plan the Niagara Falls part of your trip mid week, when wait times are considerably less than weekends.

I agree with others that this trip would involve alot of driving, with not much time to see the destinations.