The story of modern electronic digital computing should start with Alan Turing who published a paper in 1936 On Computable Numbers, with an application to the Entscheidungsproblem.  The paper proved that a machine capable of processing a stream of 1s and 0s according to programmed instructions would be capable of solving any problem that would count as a 'definite method.'  As it happens, the set of problems included in this definition is the universe of mechanically solvable problems.  Hence, the Turing Machine is also known as the Universal Machine, the theoretical precursor to the electronic digital computer which Atanasoff was soon to invent.