While it might seem that we don't get enough sleep nowadays, scientists say that we get better sleep now than we have throughout history! It seems that before the industrial evolution, people had 2 distinct sleep cycles.
People would go to bed at around 9 to 10 o'clock, and then wake up past midnight. Then they would smoke, hang out or have sex. Then they would go back to sleep. It seems the reason for this was electricity. Having artificial sources of light modified our cycles. In some studies, people deprived of electricity revert to this earlier 2 sleep cycle period.