developed by a team around Grace Murray Hopper, the first English-language data-processing compiler.

In 1951 [12]:-

... she discovered the first computer "bug." It was a real moth, which she pasted into the UNIVAC I logbook. In 1952 she had an operational compiler. "Nobody believed that," she said. "I had a running compiler and nobody would touch it. They told me computers could only do arithmetic."
Hopper's reason for designing a compiler was, she wrote later, because she was lazy and hoped that the introduction of compilers would allow the computer programmer to return to being a mathematician.

http://www-groups.cs.st-and.ac.uk/~history/Mathematicians/Hopper.html