Why was the goddess Athena considered the patroness of Athens?

When the city of Athens was built, its inhabitants could not choose a patron for a long time. The choice fell on the god of the seas Poseidon and the warlike goddess of wisdom Athena. The residents of the city decided that the one whose gift would be more valuable to the townspeople would win. Poseidon presented a horse and promised the inhabitants of the city to make them successful navigators. Athena struck the ground with her spear, and an olive tree sprinkled with fruits grew in that place. These same goddess promised power and prosperity to the city and was chosen as the patroness of Athens.