OK
Well - there are some great backroads from Savannah to Helena on the Mississippi River. This area is known as the Black Belt - not because of the race of the people living there, but because of the black soil. Of course the great soil led to cotton plantations and slaves - thus many of these counties had 80% African Americans as recently as 1950. Since then many African Americans have migrated to the north or to southern cities, but still there is a black majority. After the Civil War many plantations went to sharecropping - "Slavery" under another name - and this area remains until today one of the poorest regions of the country. It's an incredible area of the country - one that all the people taking the Adventure Cycling routes never see. I doubt that folks in these little hamlets will have seen many x-country cyclists. Do bear in mind these parameters - and also that offering someone food is an important gesture of welcome. You'll need to think about how you'll handle it.
So you have 10 weeks to get across. I'd say it will take no more than 2 weeks to the Mississippi. 4 days for each state plus 2 rest days. Plus another 10 days to 2 weeks to get to Manhattan. The stretch along the Buffalo River near Jasper in Ark is great and you will probably love riding north with a tailwind thru the Flint Hills in Kansas. So let's say a month. That gives you 6 weeks to do the rest.
You can either do a straight line across the west thru Nevada - Yosemite is possible with this route. I can get you into San Francisco thru a back way from the south with some great coastal riding - although the wrong direction as far as prevailing winds are concerned. Or you can just take the Adventure Cycling Western Express route. I wouldn't think this would take more than 5 weeks, maybe only 4. June shouldn't be too bad crossing Nevada.
Another possibility is to veer north thru Wyoming, the Sawtooth Mountains of Idaho with natural hot springs, southern Oregon, and then head down the Redwood coast of Calif to the Golden Gate bridge. This would take about 6 weeks.
How are you touring? Road bike? Mountain bike? Panniers or BOB? Are you willing to do a little dirt for the payoffs? You do know about free camping on public lands in the west, right?
And as for July birthdays - You was born on the Fourth of Joo-Lie. Any thoughts on the direction the country's going in?