state line
state boundary

The way I took led across the state line and south, then west.

So he had until they reached the state line to act.

"Isn't it against the law to bring that stuff across a state line?"

A few miles out of town I crossed the state line.

It took us two weeks to cross our first state line.

Between 1830 and 1840 nearly 250,000 slaves were taken across state lines.

Then one night toward the end of February he decided to make another trip to the state line.

The seven miles closest to the state line are nearly done; the rest will take two years.

"You didn't follow her home from the state line that Saturday night?"

The next morning, the group finally makes it across the state line into Minnesota.