Which Interstate do you want to leave Alabama on? Atlanta, Chattanooga or Nashville?
One of the places my DW visited on our honeymoon was Natural Bridge Virginia along I-81. I would advise to go I-81 through PA rather than dealing with traffic in New Jersey and the NYC area with your motor home.

My brother lives in Mountain Brook and annually drives back here to Boston to visit. He takes 81 to 84 to 90east.

New England is pretty big so it would be helpful if you gave some idea on what your interests are. Coast of Maine? Mountains of NH? Mansions of Newport? Casinos in Connecticut? Cape Cod beaches? Boston? Though the thought of driving an RV into Boston is just blowing my mind.

I think Maine is pretty RV friendly. Salty Acres in Kennebunkport seems pretty good - I'm not a camper but have walked through the campground. My friends who own travel trailers seemed to like it. NH as a lot of campsites too.

So let us know when you are traveling and what type of activities you like and you'll get lots of good advice.

Why don't you go to freetrip.com and enter your starting point in Alabama and the furthest point of your trip in New England to see how long it will take you without stopping to see things. Once you have that info you can plan your side trips along or away from the interstates.

I like using Google maps for planning. Birmingham to Boston is 1175 miles and 20 hours of driving. Pick things you'd like to see along the way and plan for overnights every 300 to 500 apart. If you want to do mountains, you can do some of the Blue Ridge Parkway along the way. Stopping in Amish country in the PA countryside is very nice. On the way back down you may want to head to the ocean and the Outer Banks and the stop in Savannah or Charleston on the way back. Where you stop really depends on your interests.

I can't imagine Brimingham to Boston at 20 hours. It can take 3 hours just to get aroun NYC and another 4 to 5 hours to get ot Boston.

Agree you need to decide what you want to see and how far you want to drive. (With an RV you really can;t see the major cities - there's no place to put it - unless you are towing a car - and park the RV an hour or more away.)

If you take 81 to Scranton and then go on 84E you avoid NYC altogether. 20 hours of actual driving time is about right. The key is to avoid 95.

Assuming a Birmingham start travel 8.5 hours to Natural Bridge.
Natural Bridge to Niagara Falls Is about 9 hours through some beautiful PA woods. Leaving Niagara Falls head for Lake Placid in the Adirondacks (6.5 hours). Lake Placid to Saratoga Springs is only 2 hours (lunch?) Saratoga to Conway NH via the Kancamagus highway is about 4.5 hours. You should be able to find a good place to camp along Kancamagus Highway (112). It is easy to add Maine to your list of states from Conway.
For the return trip, come through Scranton to the small town of Elysburg Pennsylvania to Knobels which has a nice campground with a pool next to a great amusement park.
http://www.knoebels.com/
From Knobels you can make it back to Natural Bridge for another night and then back home.

Oh thank you all so much for all of the advice!! To be perfectly honest, I'm not exactly sure what all I want to see. I know that I want to see some of the coast, countryside, and historical places as well. I really want to stay out of the big cities in this trip and just focus on the beauty and history of the area. I am so very thankful that ya'll warned me against Boston and NYC because I probably would have tried it. We will begin our trip on April 1.

People are cautioning driving in Boston and NYC. If you wanted to go into see the cities, you'd be better off parking and taking the train into the city.

April 1st? I think you might still hit real winter weather in thr northermost areas you're considering. If you;re not used to it and with an RV it could be difficult. At best, you'll be in "mud season" in some areas. Very few leaves on trees from NYC on north, so it may not be all that scenic.

The place to camp with your RV on the Kancamagus highway: http://www.kancamagushighway.com/campgrounds/jigger_johnson.htm
From Conway there is an Amtrak bus (8:45AM) that goes to the Boston South Station from there you could go to Providence RI or even to New York. On the return trip, you would have at least an hour from when you got off the NE Regional train to see a little of Boston before your bus back to Conway. The bus gets back to Conway in the early afternoon.

Double check to make sure campgrounds are open in the areas you are thinking of visiting. April 1 is early (I think) for campgrounds in Maine and NH. The Salty Acres in Kennebunkport that i mentioned earlier probably won't open until April 15 or so

If Jigger Johnson is not open, this one will be. They try to keep at least 1 open all year long. http://www.kancamagushighway.com/campgrounds/blackberry_crossing.htm
Blackberry Crossing is only 6 miles from Conway.

Also check with some of the RV specific forums. Lots of friendly people and great advice. Have really helped us in the year and a half we've owned our first RV. irv2.com RV.net and RVforums.net

I will make sure that I check out all of this!! I wouldn't have thought much about the weather considering that its 84 degree's here so thank you so much. It is becoming VERY clear that our idea of just getting in the rv and driving without any real plan might have sounded adventurous but now sounds silly. Any suggestions on places that we just MUST SEE?

It's not silly. Maybe you should just revise your route - not go so far north. With an RV you have a lot of flexibility and can look at a guidebook and plan where to go next after you are already on the road. Have you purchased a guide book yet or ordered one from AAA? If you aren't a member of AAA yet, I strongly encourage you to join - and then go pick up some great guidebooks or have them mailed to you.

Things we enjpy along or close to 81

Gettysburg National Battlefield

http://www.nps.gov/gett/index.htm

Biltmore Estate in Ashville

http://www.biltmore.com/

Memphis, Tenn Chattanooga, Tenn

Baseball Hall of Fame in Cooperstown NY

Amish Country in Penn.

Defiitely check the weather. In April you can still get sleet and cold temps in New England (I was stuck at Logan airport once in mid April when rain turned to sleet and grounded the shuttle.)

Also, once you are north of VA the countryside will be brown and crunchy. In NYC trees don;t go into leaf until late April or early May - and even later farther north. You may see green grass and a few early flowers - but the countryside won;t look like much north of DC. (Mid April is cherry blossom - the real beginning of spring. And if you are inland or at any altitude it can be even later.)

Cooperstown is fascinating - but the counryside will likely be mostly mud.

In April, Old Sturbridge Village in western MA is open daily. From there you could head to the MA/RI coast. I know there are campgrounds on the Cape that are open in April.

From Providence RI it would be about 3 1/2 hours to NH's White Mountains but that would be all hwy driving and not scenic until you get around Manchester NH. I93 actually goes thru the White Mountains and it can be pretty. Lived here all my life and still can't tell you when trees start to leaf out but to me, that's as pretty as foliage. There's the first yellowish green of willows. There's a mist of red from maples. But I think you'll be too early. But there could still be some skiing.
As mentioned, if you take the Kancamagus Hwy east to the Conway area, you are then only about an hour from Portland ME. Not sure where in Portland you can park an RV. The Old Port Area is great. Then you can take I95 south to Boston and beyond.
You don't have a lot of time and VA should be beautiful. You could find plenty to see and do without going any further north.

One of my favorite sites is at your starting point--the Civil Rights Monument at the Southern Poverty Law Center in Montgomery.
Another on your way might be Old Salem in Winston Salem NC. I think you need to get a KOA directory as well as campsite directory although I have heard you can park in WalMart parking lots, BUT that may be being phased out in some places at least.

You've gotten some great advice here. One of the best forums I know of for RV travel is www.rv.net/forum. Anything you could possibly want to know about RV's and RV travel is happily answered for you.