Classical mechanics, its laws being very close to everyday experiences and phenomena and hence very perceptible to human beings grew as one of the first sciences and has a long history. There are famous records of ancient greeks having found out many of laws governing the world around them. The law of levers, the Archimedes' principle and Aristotle's works were some developments of physics in that era.
Until about 400 years ago, study af classical mechanics was based upon philophical arguments and quantification of physical quantities and experimentation were not given much importance. At that time, Galileo performed experiments where he attempted to understand and explain phenomena with the help of numbers.
He peformed experiments with inclined planes and motion of bodies on them. He concluded, by dropping two identically shaped balls having different masses from the Leaning Tower of Pisa, that all bodies fall with the same acceleration towards the earth if air resistance is absent.
He also gave the law of inertia that is now famous as the First Law of Motion. He gave a set of mathematical transformations to relate events of different frames of reference. These transformations are classical counterparts of the Lorentz transformations used in the theory of relativity
Then came Issac Newton.