When traveling from US to Paris(where I went thru immigration) to Milan Malpensa airport and back to Paris, I did not have to go thru immigration in Italy at Malpensa airport, so even though I was in Italy my passport did not get stamped. Why is that? I asked at Malpensa but they said they dont do it...
Why is that?
Because France and Italy are part of the Schengen Zone, which essential makes travel among/between the member countries like travel from any US state to another.
Demi, The Schengen Area is a passport union. There are no passport controls between Schengen Area countries. The same applies to all Schengen internal borders, no passport checks at the land borders either. Your passport will get checked and if necessary stamped when you leave the Schengen Area.
See this map to see which countries are in the Schengen Area: https://ec.europa.eu/home-affairs/sites/homeaffairs/files/schengen_map.jpg
BTW, as a non-European, you are allowed "90 days in any 180" in the Schengen Area as a whole.
As Joe and Chris explained above.
We've entered Europe a couple of times through Schiphol in Amsterdam enroute to Italy or another Schengen country so that's where we've gone through immigration. You do it at the first point you enter the Schengen, which in our case was the Netherlands. It's a good reason for making sure a connection allows a healthy margin of time to get through the immigration process.
Be glad that you didn’t have to through passport control a second time! Lines can be very long.
If you land in London or anywhere in UK you go through passport control and then you have to go through it a second time in continental Europe as the UK is not in Schengen.
All the more reason to avoid the horror that is Heathrow Airport.