The history of the central theorem starts with Laplace at the end of the 18th
century. Sums of independent random variables had been studied for many
different error distributions before 1810 when Laplace release his first paper about
the CLT. However, they had mostly led to very complicated formulas. In Laplace's
probabilistic work sums of random variables played an important role from the
beginning. Already in one of his first papers of 1776, he was working on
calculating the probability distribution of the sum of meteor inclination angles. He
there faced the problem of the deviations between the arithmetic mean of the data
(which were inflicted with observational errors) and the theoretical value. He
assumed that all these angles were randomly distributed following a rectangular
distribution between 0° and 90°. Due to the considerable amount of celestial
bodies, he was not able to perform an exact calculation and he thus needed an
approximation [Fis]. It was in the process of finding an approximation to this
problem that Laplace eventually came to form the first versions of the CLT.