He was appointed to cabinet on October 7, 1975 as a Minister without portfolio responsible for Housing, and was promoted to Chairman of Cabinet on February 3, 1977. Re-elected again in the 1977 election, he appointed as Minister of Government Services on January 21, 1978, and as Minister of Agriculture and Food on August 30, 1979. Henderson was most proud of his work in the Agriculture portfolio, although reviews from the farming community and his department staff were often less than flattering.