It enters the Union as a free state in 1820.

By 1850 California entered the Union as a free state.

It had entered into the Union as a free state.

Maine entered the Union as a free state in the compromise to balance Missouri.

At the heart of the conflict was the question of whether Kansas would enter the Union as a free state or slave state.

It entered the Union as a free state, and In Cold Blood happened there.

California entered the Union in 1850 as a free state; the other areas would remain territories for many years.

When California entered the United States as a state in 1850, Americans began to move into the area.

Some states, such as North Dakota, entered the Union as a "dry" state.

When Oklahoma entered the union as a state, it did so under a constitution more biased than Mississippi's.