Long interested in municipal affairs, he entered civic politics with his election to the Edmonton Town Council in 1903.

Retiring after one term in office and returning to his contracting firm, he eventually left Edmonton in 1922 for Vancouver, where he lived for 10 years leading up to his death in 1932.

A Liberal in politics, he is remembered as a progressive mayor whose policies helped the accelerate development of city of Edmonton.

[1] Charles attended and completed public schooling in Wellington County, and around 1871 the May family relocated to Paisley, Ontario.

[2] He then gained employment as a carpenter and builder with the Manitoba and North Western Railway, where he was tasked with building rail bridges and stations.

He joined the contracting firm of Murray & McDermot, serving as foreman on various projects, including the building of the Manitoba Hotel.

[2] He was also involved in the construction of the Clover Bar railway bridge, for which he set the concrete piers and foundation, as well as the Land Titles Building in Regina, Saskatchewan.

[14] As the popular choice leading into the election,[15] he handily defeated fellow councillor Arthur Cushing by a count of 627 votes to 355, and thus became mayor of Edmonton.

It was during May's term as mayor in which the municipal foundations of Edmonton were set; he oversaw the purchase of the road maintenance equipment, the city's first telephone system as well as the upgrade of the street car system to steel rails and posts, purchase of land for municipal use,[16] paving of roads,[17] and negotiations for the establishment of a manufacturing plant in the city.

[26] He moved to Vancouver, British Columbia in 1922, and following a long period of illness, he died of stomach cancer there on March 1, 1932, aged 73.

[27] The 1912 publication, History of the province of Alberta, praised May's stern and ambitious personality, stating that "in the most adverse circumstances [he] endured with fortitude".