I checked with Hercules, they are made in Thailand, probably by the same guys that make Maxxis.
I have had bad experiences with Goodyear car tires over the years, I had one great set and they discontinued my size.
I have had Marathons blow out on a cargo trailer a few times, one old, one new-ish.

The Greenball Towmaster and Hercules 901s are the only St225/75R15 LRF tires I have seen so far.

I do remember my dad getting Uniroyal tires for the car back in the 80s. They went out of round after a year, made in Opelika AL.
My dad's cousin was the plant manager that recommended them.

 

How do you like the 298RE? I just picked up one of the last ones made. What year is it?
You swapped out the springs when you added the EZ-Flex, what are the new springs rated for?
I was looking at the MORyde shackles and LCI shocks based on a recommendation, but I will research more.
I added a ProPride when I picked mine up and it towed great from Chicago to Texas empty. We'll see how it goes to Georgia and back loaded with the kids and dogs!

 

We really like it. Almost too large, but not. If you know what I mean. 2014 model.
I put the 5 leaf 5200lb springs on it as I didn't care for that close to maxed spring loads on it.
Did it all at one time. Jacked up one side, pulled the wheels and had the wife take them to be swapped at tire shop for the Maxxis 10 ply tires I had bought online.
While she was gone, I pulled the springs and added the EZ Flex and wet bolt kit to the mix and then did the other side.
I scored the EZ Flex in an open box for $150 to the door, springs just over $120, around $480 for the tires mounted at $10 each.

Griz

 

Sounds good, I am just starting my modifications, but at least I acquired a bunch of needed items while I was renting trailers from Ft Sam.

 

This is probably the most contested topic out there.
Politics, religion, trailer tires.

Been reading about (and dealing with) trailer tire failures since April of 2008 on our factory new trailer.

Long story short: I upgraded rims from 15" to 16" and mounted Michelin LTX E load.

Tread separation, blow outs, repairs, warranty, dealing with manufacturers... the whole nine yards. If you're interested I've got a bunch of posts chronicling my experience at my blog. Just enter "marathon" in the search bar.

 

Trailer tires........go commercial grade or go home!
These are the two worst ones of the six with 20,000 miles on them. SAILUN S637 LR G


Your $85 dollar “RV” type trailer tires are junk rags, regardless of where they are made or what brand they are.