Which event initiated the yom kippur/ramadan war?

arab nations cut off american oil supplies.
israeli troops advanced across the suez canal.
israel launched attacks against egypt and syria.
egypt and syria launched a surprise attack against israel.

The transcontinental railroad provided a means of fast transportation. it cut a 6 month trip into 6 days, created jobs for many people and encouraged immigration. the homestead act played a huge role in western expansion; it allowed settlers to begin a fresh start, and gave them land in exchange for their residence for up to five years and a small fee.