Why do states have capitals and how do they choose the states capitals?

Question

my sister really needs to know this question for school and i need the answer soon

Answer 1

The capital is the seat of that state's government. Most government business is done there.

The capital is usually decided by the state's legislature, sometimes by voters

Answer 2

Historically there were no states.  There were city-states, basically each city controlled themselves.  As cities gained more power they started controlling neighboring cities and became nation-states.  That could essentially be the beginning of capitals, but you're referring to state capitals, so heres an answer on that:

It all comes down to communication.  They have capitals, because they need a centeral city to host all of their important government buildings and bureacracies.  They didn't have internet and telephones in the old days, so they needed to be close enough together to quickly communicate between the main branches of the government.  They chose their state capitals based on importance at the time.  They would generally pick the largest and most important city in the state, since thats where the most economic activity and production would take place.  In modern times, however, its not necessary since we have so many methods of instant communication and quick travel like airplanes and freeways.  Hence you get modern capitals like Canberra Australia and Brasilia, Brazil which location and city importance wasn't an issue anymore.  

Capitals are losing importance.  Example, even though Washington DC is our nations capital, the President and the heads of different Departments are rarely in Washington.  They administer the government from anywhere in the world thanks to modern communication.