Paperwork for traveling within the EU with US passport

You really do not need to do anything to cross from Belgium into France on the train. No passport or "papers" will be checked unless it's some sort of special circumstance. In fact you really won't know when you cross the border unless you are looking at a map.

There is a fast train from Brussels to Paris that is easy to book. If you book ahead it will be less expensive. Does your cruise drop you in Brussels or is your last stop in another town?

When are you traveling?

What do we need to cross international borders with a US passport?

A train ticket.

Start by reading this: https://en.wikipedia.org/wiki/Schengen_Area

For the most part the cross border checks have been eliminated. A couple of decades back the Schengen zone agreement was signed that eliminated border checks for most (not all) of the European countries. Goggle Schengen zone for a list of countries participating. You go through immigration and custom on your arrival in the first Schengen zone country. After it is like traveling between the states. However, do carry your passports because random checks are possible.

We're travelling from Amsterdam airport to Paris on the fast train which we 've already booked. May 3rd. I booked first class because I wanted to be sure I could cancel without penalty. This trip has already been cancelled twice(2020 and 2021) .

I just found this forum and I'm trying to find answers to many questions of being on our own in Paris. I know this is the wrong place, but I've been trying to find the discussion of the Navigo Decouverte pass, particularly, I saw mention that the photo we attach can be a photocopy of passport picture or driver's license???? Can someone point me to the right discussion?

You can just make photocopies of your passport picture page then cut it out for the Navigo Decouverte.

What days of the week will you be in Paris?

And welcome to the forum! Lots af excellent advice here !!

If you do a search you'll find lots of posts about getting around in Paris, including the Navigo.

Every train station has dozens of photo booths, which specifically advertise that their photos are made for ID cards. Larger metro stations have them too.

Passprt pictures are too big for the ND -- you want a 25/30mm headshot -- cut from a snapshot or copy a driver's license or copy/reduce the passport photo.

I easily cut down the photocopy of my passport picture to fit the Navigo dimensions. If you are in doubt and doing this at home, just shrink it a bit on your printer.

Clarification. We're traveling from Amsterdam Schiphol Airport on the train through Brussels to Paris. Is there no border control getting on a train? My husband just noticed a website that said we had to get a visa to go to France. I am thoroughly confused

No visa is needed for US passport holders to France. Do you have the website he saw that on? I'd not believe anything from that because that has not been the case for years and years and years! My first visit to France was 1973 and we did not need visas even then!

There is no Passport check when boarding a train in the Netherlands heading for Belgium or France.

There IS a Passport check when boarding the Eurostar from Amsterdam to London but you are not doing that.

There are many European countries that are members of the Schengen Agreement. That allows people and goods to move freely thru all Western Europe countries.

https://en.wikipedia.org/wiki/Schengen_Agreement

The last time my US passport was checked as was those of everyone else was in 2007 going from Germany to Paris, both the French and their German counterparts got on to get to work checking passports. Prior to that I had seen them chit chatting in French. A good number of the German border staff spoke French.

However, in the summer of 2015 because of so many migrants trying to get across border, once over the border from Austria to Germany, the Bavarian police got on immediately, told everyone (in English) to get out their passports and visas, obviously referring to those nationals who need a visa to visit Germany, such as the two twenty-somethings behind me. They were talking Mandarin.

The Bavarian police took off six (guys and girls) who had no tickets, all from Pakistan, Afghanistan, Iraq, etc. They were addressed in English.