[1] He served as president of the Niagara South Plowman's Association.
[1] He was elected to the Ontario legislature in the 1967 provincial election, defeating Progressive Conservative candidate Gordon Taylor by 107 votes in the new riding of Welland South.
[3] Haggerty was returned by much greater majorities in Erie in the elections of 1975, 1977, 1981, 1985 and 1987.
[1] During his 23 year tenure, he served as a backbench supporter to Liberal leaders Bob Nixon, Stuart Smith and David Peterson.
When the Liberals took office in 1985 he served as a parliamentary assistant to several ministries including Government Services and Consumer and Commercial Relations.