In 1943 Aloys P. Kaufmann became the fortieth Mayor of St. Louis.
With the death of Mayor Becker, Kaufmann succeeded to the Mayor's office according to the provisions of the City Charter. In November of 1944 St. Louis voted so heavily Democratic that it saved the state for the Democratic national and a state ticket. But it elected Republican Kaufmann to fill out the unexpired term of Mayor Becker.
During his first year in office, Kaufmann helped outline the Post-War Public Improvements Program which became the $43,000,000 City bond issue, passed on August 1, 1944. Among the 11 items voted in this bond issue was one for airport expansion. The size of Lambert Field Municipal Airport was increased from 350 to 1400 acres.
Mayor Kaufmann wrote a 36 page plea for the enlargement of St. Louis boundaries, to the Missouri Constitutional Convention of 1943-1944. He said: 'St. Louis had outgrown its established boundaries and had expanded far out into the County of St. Louis. The urbanized area contiguous to St. Louis of right ought to be reorganized as a part of the City. The Constitutional Convention is urged to extend the boundaries of St. Louis to coincide with its normal growth and expansion as was heretofore done on four different occasions.'
Some of the most important legislative achievements during Kaufmann's administration included the following. The Rat Control System of the Health Department was established in 1946. A Division of Refuse Collection was added to the Department of Streets in 1947. The first St. Louis Earnings Tax Ordinance was passed in 1946, but was declared unconstitutional by the Missouri Supreme Court, because it said the State Legislature had not granted such a right to tax the City of St. Louis. All collections were returned. The first effective Earnings Tax became law in 1948, after an Enabling Act was passed by the Missouri Legislature. A new City Building Code took effect in 1945 and was revised in 1948.