Passport and SSN are national ids. They are issued by the Federal government, so it is nation wide database. On top of that, states have their own ID systems.

Passport and SSN are national ids. They are issued by the Federal government, so it is nation wide database. On top of that, states have their own ID systems. Typically there are 2 options: just a state ID or driver’s license, that serves also as an ID. Most people in the US get driver’s license early(permits as early as 15), so there aren’t that many who has just the ID. Now, SSN is issues upon birth. Before you know it, you can already start paying taxes. For passport you need to apply, typically you would need it if you wanted to travel outside of the US. Otherwise, you rarely need it. This is because for the most part you deal with state bureaucracy, as most of the day to day life falls within state’s jurisdiction. Driving, getting married, divorced, buying things like a vehicle or a real estate, opening a bank account, domestic aur travel, etc. Some can live their entire lives without a passport, because a state ID will suffice. Even for things like voting in federal elections - you don’t need a passport. Contrary to many people’s beliefs, in the US the states vote, not people. This is/was by design. Now it gets more centralized, but the original concept is close to EU in terms of states autonomy. This means, that even for federal elections procedures vary greatly by state (its been on the news a lot lately). Moreover, you aren’t required to have an ID. It is not illegal not to have an ID or be off the grid. Before 9/11 you could even go to Canada using state ID only. Now I think even it’s possible, probably only if you have some special kind of ID. This is how things have been until recently. Then REAL ID came around. Because states rules governing ID issuance, they vary greatly. So we ended up with some states’ IDs that were as easy to counterfeit as printing a piece of paper. Some states would not do a due diligence verifying your name or address and would just take your word for it. READ ID is to addresses: mandates minimum protection level, due diligence a state needs to do to confirm address, etc. New federal regulations does not allow air travel with state ID that don’t comply with REAL ID requirements. Few states still don’t, so residents of those states will need passports for domestic travel. I think this trend will continue beyond air travel. States aren’t required to share this data with federal government or each other. It is, however, a requirement for REAL ID. At the same time there are many businesses, that specialize in aggregating various identity information a out people. Credit bureaus are such businesses as well. They aren’t only in business of credit checks, but also identity verification, employment verification, etc. Some of these companies have federal, state and local agencies among their clients. Fun fact: you can board a domestic flight without an ID. For example, if you lost it. TSA has a procedure to establish your identity. This includes asking you a bunch of facts about your life, such as where you lived in year X, last 3 cars you owned, your spouse full name and birthday, etc. I suspect they maybe using one of the credit bureaus identity verification product offerings.