Thank you. After seven trips and some 180000 miles I am beginning to feel I know a little. There's still lots I have not seen, and I have never visited and driven in winter weather. Something we Ozzies are not too keen on. lol
I do feel for you, however, as I am one of the lucky ones who has a B1/B2 visa which allows a six months stay to visit with my children and grandchildren. Six months in US... six months in Oz... helps me avoid winters in both places.
This is a popular misconception. Sure the country is not as geographically spectacular, but that does not mean there are fewer tourist attraction. However, they are more based on history especially the history of the early European settlement of the US and the associated wars. Check out the National Parks site, and see just how many NP properties there are in each and every State. Not all NP properties are nature parks, some, just like in Oz, are historical sites.
Once you get to DC you have the Smithsonian as well as all the national monuments. You could spend a week there and not see it all.
Even the midwest States have a lot of history, with explorers routes, original native settlements, and the pioneering history as well as agriculture today. Worth reading up on, so you can talk about it while you pass through those areas. (I still find the 1930s dustbowl area amazing. If you have seen any of those movies you can visualise it as you drive through the area.)
There are of course the commercial touristy glitzes as well. Yeah! there is a lot to see as you travel around the country. and when you venture off the main highways, there are countless smaller gems in local communities. All it takes is to ask locals where they would go if they had a weekend off. They will happily tell you about their favourite spots. Spots you are not likely to find on the internet or in tour guides. If only for that reason, I would leave all your travels flexible. You have the time to do it.
Glc asked the very question I should have, though I assumed it would be around June, July, August and September, since you posted in the summer forum.
Have you checked through some of the Field Reports in that forum. Especially the ones which go for several pages. These are usually the trips which lasted for many weeks... if not months.
What input are the children having into your plans? Both are old enough to have some input to make it more exciting for them.
I think you will find that map extremely useful, but don't underestimate the value of the Rand McNally with its individual State maps. (order it now, and you'll have it in a couple of weeks.)
I take it you are Perth based? In which case I would urge you to take your WA RAC membership with you. It will give you access to free maps and tourism information from the AAA all across the country. I like to travel with AAA maps, the Rand McNally (in which at the end of the day, I highlight all the roads on which I travelled that day), as well as my gps (which is used to find specific addresses in urban areas.
Enjoy the planning.
Lifey