MacLean was born in 1844 to Allan and Jane McPhadden married 8 Mar 1820 [GROS Data OPR 551/1 -2] [1] in Cornaigbeg Tiree, Scotland.

Originally en route to Honolulu with plans to enter Hawaii's sugar beet industry, he instead continued to Granville, today known as Vancouver.

(Arthur Ross already was familiar with Granville, having recommended the town to serve as the western end of the Canadian Pacific Railway.)

In February 1886, he worked to petition the provincial legislature to incorporate and rename the town, and as a result, on April 6, the city of Vancouver was formed.

Following the inferno, MacLean and his council members successfully convinced Governor General Henry Petty-Fitzmaurice, 5th Marquess of Lansdowne to give the military reserve in Burrard Inlet to the city, which became Stanley Park.

[1] In December 1886, MacLean was re-elected mayor, having run on a platform to extend the franchise and to restrict the property rights of the city's ethnic Chinese residents.

[1] MacLean was greatly focused on the completion of the Canadian Pacific Railway, calling it "the placing of the keystone in the arch of confederation;" after three months of unofficial use, the first official train arrived in Vancouver on 23 May 1887.