D.to provide the means to transport military aid more quickly in the event of a national military crisis
The Federal Highway Act of 1956 was initiated to give troops access to various parts of the US more readily if the state were attacked. In fact, the highway construction was partially paid for by defense funds.
It might be because they did live peacfully u never know because u were not there when it happend.
They use a system called "Checks and Balances".
