The law has indeed changed over time, but that is the nature of common law, it changes as new challenges come up where novel arguments will arise. That doesn't

The law has indeed changed over time, but that is the nature of common law, it changes as new challenges come up where novel arguments will arise. That doesn't make the law fuzzy though, it's clear enough for the vast majority of cases that occur at any one time. The actual statute upon which the law rests is in the constitution, I'm not aware of any changes to that since 1791.