Selma to Montgomery is just so important.
There is the Selma to Montsomery National Historic Trail - -
but many parts of it are on 4-lane US 80.
Old US 80 on the Selma end was the actual highway used.
Then there are county roads in western Montgomery County -
esp. Old Selma Rd. - but this would not be the actual route.
(However, it would give you a much better feel for 1960s highways.)
The NPS visitor center is on a busy stretch of 4-lane US 80.
US 80 was a 2-lane highway in 1965.
That roadway is mostly the westbound 2 lanes now - with almost no shoulder.
The eastbound side is newer with a shoulder some of the way.
And most people would want to ride eastbound from Selma - like the marchers.
But there are long eastbound stretches with little shoulder and fast traffic.
In Selma, Brown Chapel AME Church and museums are all close to the Pettus Bridge.
And with the new bypass, the Pettus Bridge has far less traffic.
You can see the Alabama capitol from Dexter Ave. Baptist Church.
And the Rosa Parks Bus Boycott Museum is only a few blocks west.
The question becomes - Is it worth riding on 4-lane US 80? It is dangerous.
Because the NPS visitor center is roughly halfway between Selma and Montgomery.
Plus, there are the march campsites and the memorial where Viola Liuzzo was shot.
I suggest taking the old highway and county roads.
You still have to get on a stretch of US 80 near Benton - some shoulders.
Then take Benton/Jones Bluff/and Old Selma Rds.
You can take White Bluff Rd. down to the NPS visitors center.
Rural US 80 has about 8000 vehices Dallas Co.; 10,000 Montgomery Co.
The Pettus Bridge has 13,500. Coming into Montgomery 20-25,000.
Old US 80 southeast of Selma has about 2500.
The county roads have 100 to 300 to 500 cars per day. Your choice.
I do wish this route were more bicycle friendly.
PS - There's camping at Prairie Creek Park just north of Benton.
Possible route:
https://ridewithgps.com/routes/38089330