Where to purchase train ticket from US for travel in France?

At www.sncf-connect.com

Thank you, but I cannot find the English translation on this website. Are there any other website recommendations?

Try this url
https://www.sncf-connect.com/en-en/

Most European Railway websites have an English version, but you may have to look for it. Either at the top, or at the bottom. In this case you scroll down, and you will see a drop down where you can select the country.

You could look at Seat61 for advice on train travel.

www.seat61.com

As mentioned, SNCF is the place to buy tickets. They are the ones that actually operate the trains—every one else is just a reseller.

if you find sncf hard to use then try trainline.eu. It is very user friendly and can be easily set to English not that you really need that for a train schedule. It also produces easily downloaded tickets. We have even sometimes found it a bit cheaper which makes no sense since there is a small fee in the ticket price. It lets you see the schedules and plan even if you decide to use sncf to buy.

www.trainline.eu

When you go to the SNCF website up in the right hand corner is where you click on English (sometimes a British flag on websites) to get the English version. Also download the app. It’s super user friendly and your tickets/QR codes will be there for quick easy access when you need them. I found the app so convenient when in France a few months ago.

I buy all my train tickets from the Trainline app, and have for many years. It's convenient because you won't have trouble with your credit card, it has a better search algorithm than SNCF, and your tickets are stored in the app as a QR code. Very easy and user-friendly.

The British flag is the symbol for English language, not the US flag. Sometimes hard to find. I usually check the "corners".

I second Trainline. Used them with ease and no surprises.

I second Trainline and Seat 61. Have used both a lot. Do you use the free Google translate app? I have translated sections of text using it with my phone's camera. I was in Annecy for the first time a few months ago (off season) - really enjoyed it.