Passport Control Marseille France

You will pass the passport control booth in Frankfurt and you both get processed together. This will be on your way to the connecting flight. Everything is well marked in both German and English.

So, we only have 1 hour 30 min., to get to our flight to Marseille. Will that be enough time to get through Passport Control and get to our gate?

Don't worry. That is enough time otherwise the airline could not sell the ticket.
If the first flight is late causing you to.miss the connection the airline will just put you on the next available one.
It looks like Lufthansa has 3 flights a day direct to Marseille, which one are you on?

We are on the 9:10am flight

Also, will we then go through Customs/Immigration at Marseille Airport?

Also, will we then go through Customs/Immigration at Marseille
Airport?

No -- when you arrive in Marseille it will be like arriving off a domestic flight. You land, collect your checked bags (if any), then leave the airport.

Thanks so much for info!! I like any tips for smooth maneuvering of airports.

A phrase you will see a lot on this forum and elsewhere is "Schengen Area".
The Schengen Area is a "Passport Union", you get your passport checked when you first enter the Schengen Area, and not again until you leave. The Schengen Area contains 26 countries, including France and Germany.
This is why your passport will be checked in Frankfurt, this is where you enter the Schengen Area; and not again in Marseille as Frankfurt - Marseille is a Schengen-internal flight.

And the airline would not have allowed this connection if it wasn't possible. They are responsible for getting you to Marseille in case of delays.

when you arrive in Marseille it will be like arriving off a domestic flight. You land, collect your checked bags (if any), then leave the airport.

While you won't go through passport control/immigration in Marseille, you may very well go through a truncated passport check there. The last 2 years we flew into Lyon from the US, going through immigration in Munich. However, we also had our passports checked in Lyon. I wasn't surprised last year, because France still had a state of emergency, but I was surprised this year. However, it wasn't a full passport control; no running the passports through a scanner. In fact, I don't think the agent even opened our passports.

To get technical, you will go through customs in Marseille, but you might might not even notice. Since your bags are checked through to Marseille, that is where you will get them, then walk out the "Nothing to Declare" door. You could get spot checked there, but it has never happened to me or anyone I know.

The only other piece of information that may be useful, depending on how Munich is set up, is that you want to look for directions for connecting flights, as opposed to final destination.

The difference is that the line may be shorter, and you stay in the secure zone. Otherwise you wind up going through security again.

As first-timers, you will benefit from rehearsing how to get into the city from Marseille Provence airport. There is a train, but also lots of buses. Both arrive in approximately the same area of downtown Marseille. The airport has an especially useful website with lots of explanations:
https://www.marseille-airport.com/

So, we only have 1 hour 30 min., to get to our flight to Marseille

Is the air travel a single booking?

If the first flight is late causing you to.miss the connection the airline will just put you on the next available one.
It looks like Lufthansa has 3 flights a day direct to Marseille, which one are you on?

This is true only if it is a single ticket/booking.

I cannot find a single booking itinerary from ORD-FRA-MRS, that has a layover in FRA of less than 1h 55m. You say you have 1h 30m layover.

If you purchased an ORD-FRA ticket and a separate FRA-MRS flight then you would have to buy a new FRA-MRS ticket if you miss the flight due to getting to FRA late.