The history of the fundamental theorem of calculus begins as early as the seventeenth century with Gottfried Wilhelm Leibniz and Isaac Newton. Leibniz looked at integration as the sum of infinite amounts of areas that are accumulated. As such, he references the important concept of area as it relates to the definition of the integral. Isaac Newton used geometry to describe the relationship between acceleration, velocity, and distance. This is key in understanding the relationship between the derivative and the integral; acceleration is the derivative of velocity, which is the derivative of distance, and distance is the antiderivative of velocity, which is the antiderivative of acceleration. In 1823, Cauchy defined the definite integral by the limit definition. Also in the nineteenth century, Siméon Denis Poisson described the definite integral as the difference of the antiderivatives [F(b) − F(a)] at the endpoints a and b, describing what is now the first fundamental theorem of calculus. It wasn’t until the 1950s that all of these concepts were tied together to call the theorem the fundamental theorem of calculus.