I feel like this lack of trust is a relatively new thing, in the last 25 years or so. I grew up in the US (suburban NJ, and later semi-rural MD) in the 80s and 90s, and it was completely normal for me to just yell "Mom, I'm going to Mike's!", hop on my bike, and ride down the street. When we lived in NJ I would walk to and from the school bus stop (maybe a half mile away) by myself every morning and afternoon.
Things took a turn for the weird by the time I was in college; one summer I wanted to take the bus up to NYC to visit a friend, and my mom (who, remember, had no problem with me just taking off on my bike when I was 8) was absolutely terrified that I'd be killed. She gave me her cell phone for the trip and insisted that I call her any time I were to leave or arrive somewhere. (This was all before 9/11.)
I don't remember any sharp change in her attitude toward this at any point, so I can only assume it was a gradual thing.
In fairness, Koch/Dinkins-era NYC (the 80/90s) was pretty gnarly, with far higher crime rates than today, so I'm not surprised your mom was worried. I also had free reign of my suburban NY neighborhood, but no way my parents would have let me go explore the city solo.
I did live in Manhattan for one summer in the mid-eighties when I was in grad school--quite a bit post-college. On the one hand, I (probably rationally) didn't worry about walking down Fifth Avenue or around the West Village late at night. On the other hand, there were definitely areas of the city where--if the kinda fear that if I screwed up with the metro express stops I'd be stepping out of the subway into a hail of bullets was not actually the case--I was probably also much safer to avoid certain areas. And something like 42nd Street late at night was pretty awful.
The war on terror had a huge price tag and there is no sensible opposition. Formerly mainly driven by conservatives, liberals now seem to be afraid of 14-year-olds on the internet with predictable results.
I hope saner and calmer voices prevail in the future.
Things took a turn for the weird by the time I was in college; one summer I wanted to take the bus up to NYC to visit a friend, and my mom (who, remember, had no problem with me just taking off on my bike when I was 8) was absolutely terrified that I'd be killed. She gave me her cell phone for the trip and insisted that I call her any time I were to leave or arrive somewhere. (This was all before 9/11.)
I don't remember any sharp change in her attitude toward this at any point, so I can only assume it was a gradual thing.