I am traveling through the US for six weeks from the end of April.
I am a rancher back home and wear a Leatherman tool on my belt daily.
What may one carry in the US? I would not display one openly, but I assume that a Swiss Army knife in the pocket is okay? The Leatherman I could keep in my main luggage.
I won't take either in my carry-on for the plane trip
Please advise.

Depends on the state. No knives in airports or in any state/federal buildings, courts or installations for sure.

Here's a link to knife laws in all 50 states:
https://www.akti.org/state-knife-laws/

Thanks very much. I'll have to check each state but reckon the two multi-tools mentioned are pretty safe, especially if in my main luggage and not on my person.

That link to state knife laws looks quite useful. I almost always carry a small pocket knife. Will head back to Houston after a couple weeks in Japan and my pocket knife is safely in a checked bag. For any trip I try to make sure I'm not taking an especially prized or expensive knife. As usual having one on the trip has come in handy several times. I'm rather circumspect when using one in public and assume it's might be against local rules or practice - even in the states.

Safe travels,

Heck I wear a Leatherman 365. Only when I have to pass a metal detector to enter a courthouse or an airport do I leave it in the truck.
I was taught by my father and by the Boy Scouts always to be prepared, and carrying a Leatherman is highly useful in that role.
And by the way, fuck the knife laws in the U.K.
Welcome to America, Karoo. Have a great trip!