Although the panama canal is 51 miles long, it’s two entrances are only 25 miles apart. how can you explain this?

Because of the route of the canal.

Explanation:

IN order to make it affordable and possible the Panama canal works with levelers that rise up and then low down the boats, this levelers and chambers had to be digged up, so they had to search for low lands and plains where making this arificial bodies of water were possible, that is why the route of the canal is not a straight line and it´s rather a zigzag among the panama land.

b.   jim crow laws were enacted in northern states.