After the war, Brown was employed by Montgomery Ward and was promoted to Assistant General Operating Manager within eight years.

Merseles died suddenly in 1930 and Brown was appointed president at the age of 35.

[6] During World War II Brown served as an advisor to General Levin H. Campbell, Jr. After World War II, at the request of General Lucius D. Clay, Brown wrote a book entitled "A Report on Germany" (Farrar, Straus and Company, New York, 1947), which served as a detailed recommendation for the reconstruction of post-war Germany, and served as a basis for the Marshall Plan.

Brown died from a heart ailment on February 27, 1951, at age 57, in Delray Beach, Florida.

He was buried in Putnam Cemetery in Greenwich CT.[7] In 1984, thirty-three years after Brown's death, Johns-Manville was alleged to have prioritized profits over the health and safety of employees during the time of his leadership.