Which federal law do you interact with the most? Someone made the argument that it’s federal tax law, but I disagree. Here’s my thinking on which Federal laws people interact with the most.
Where the National Minimum Drinking Age Act of of 1984 federally sets the minimum drinking age to 21, I would buy that the most common interaction that everyone, not just citizens, residing in the US, is with that restriction. Most people only deal with federal income tax once a year, while most everyone who drinks has their ID checked at every interaction. Pedantically, the law indirectly sets the age for purchasing (and not consuming or possessing) alcohol to 21 by punishing states for not having laws against that, and doesn’t directly set the age to 21, but it’s effectively the same thing.
Another one that comes to mind is KYC/AML laws for financial transactions by the Bank Secrecy Act of 1970. That field in Venmo for “what’s this for?” If you write drugs, or crimes, or terrorism, they have to take it seriously. If you move just $3400 of money around 3x in a month, that’s considered structuring and is suspicious. Most people don’t try and pull out or put in $10k in cash, which would be the biggest interaction with the AML laws, but if you have a bank account (which is only 95.5% of US households), you’ve interacted with the KYC aspects of the law.
Cannabis is still federally illegal under the Controlled Substances Act of 1970 and a lot of people interact with cannabis on a daily basis. Federal law still influences state behavior, so even in states where it’s been legalized for adult use, arguably there’s still an interaction with federal law there. Jobs in legalized states can still drug test and fire people for cannabis.
Other substances under the same act that are controlled are also relevant. If someone has ADHD and has a prescription for regulated stimulants, they have to interact with federal law every time they fill their prescription just in case they’re secretly Scarface with their 30 pills per month. The number of people with ADHD is far fewer than alcohol drinkers, so this is further down the list, but believable stats on the black market are hard to come by.