Early civilizations always formed near rivers/river deltas. Rivers provide water, silt (fertile soil) which is good for farming, and transportation, as well as natural barriers (such as the cataracts-rapids-in the Nile) which protected the Egyptians from invasions/attacks. The Nile is also predictable in it's seasonal flooding (compared to other early civilizations' rivers), which was good for the Egyptians.
(All of those factors influenced the development of the Egyptian civilization.)
