How was rocket fuel developed?

Rocket fuel has been developed through a combination of scientific research, engineering advancements, and trial and error. Early rocket fuels were based on liquid oxygen and hydrogen, while modern rocket fuels incorporate a variety of propellants such as liquid hydrogen, RP-1 (a type of refined kerosene), and solid fuels like ammonium perchlorate composite propellant (APCP). The goal in developing rocket fuel is to create a propellant with high energy density and efficiency to generate the thrust needed for space travel.