After drinking alcohol, how long is there a presence of ethanol in your body

Our bodies, being the wonderful organisms they are, tend to get rid of ethanol as quickly as possible as soon as it enters the brain. The brain, knowing that ethanol is toxic to the body and specifically the liver (as the liver cleanses our blood) triggers our metabolism to flush out ethanol almost immediately. I don't know the exact time limit but a matter of just hours would be a good assumption.