[2][3] In the 1880s, Johnston was restricted from attending public school due to Nova Scotia's segregation laws.

His family had been long-standing members of the Cornwallis Street Baptist Church and he followed this well-worn path, becoming an officer of the church, President of the Baptists Young People's Union, superintendent of the Sunday School, and a member of the finance committee.

In 1899 he became a field missionary thus helping to support other Black Baptist churches throughout Nova Scotia.

His network of contacts and influence grew through his membership in organizations such as the Aetna Club (President), African Baptist Association (Secretary), Coloured People's Celebration Committee (for the 50th-anniversary celebrations of the African Baptist Association), Order of the Good Templars (District Chief - the higher position in Halifax), Independent Order of Oddfellows (Secretary), and joined the Freemasons' Union Lodge (Master).

He along with orders in the community continued to lobby for the school and in 1914 had the idea presented to the Halifax Board of Trade and the Nova Scotia Legislature.

In 1915, one month after his death, the Nova Scotia Government passed legislation making the school a reality.

[2] On the evening of March 3, 1915, after returning from work to celebrate his wife's birthday, he was shot twice in his home by his brother-in-law, Harry Allen.

On February 26, 1902, he married Janie (Jennie) May Allen in Windsor Junction, Nova Scotia.