So I'm kind of confused about who was and wasn't inspected. Was the inspection only for people intending to remain permanently or intending to start a naturaliz

So I'm kind of confused about who was and wasn't inspected. Was the inspection only for people intending to remain permanently or intending to start a naturalization process? Was this based on what travelers said their intentions were, or the kind of transportation they used, or something else? My intuition is that someone coming as a tourist, for instance, wouldn't have been subject to this level of inspection. But I also suppose that was much rarer at the beginning of the 20th century than today. (I also don't know what happened at the land borders in prior centuries.)