His most widely known novel Johnny Gibb of Gushetneuk, paints a vivid picture of economic and social relations in a rural parish in Aberdeenshire during the 1840s, against the background of the Disruption in the Scottish Kirk.

[1][3][4] Alexander established himself as a writer with the help of the Mutual Instruction movement which flourished in North-East Scotland at this time under the direction of William McCombie of Cairnballoch, farmer, philosopher, economist and newspaper editor, who gave him a job as reporter and chief clerk of the Aberdeen Free Press in the autumn of 1852.

[6] His assiduous reporting on the cattle disease rinderpest after it reached Aberdeenshire in June 1865 assisted the development of effective local measures to limit its spread.

[7] Alexander was a prolific novelist of wide thematic range and considerable variety of style, from austere realism at one end of the scale, to mellow social comedy at the other.

[2] The speech of his characters was rendered in an orthography which sought to convey the sound system of Lowland Scots in Central Aberdeenshire in the middle of the nineteenth century.

The Authentic History of Peter Grundie appeared in the Penny Free Press in 1855, and is the earliest novel of substance to be written specifically for publication in a Scottish newspaper.

"[9] Alexander's later short stories, Mary Malcolmson's Wee Maggie, Baubie Huie's Bastart Geet, Francie Herregerie's Sharger Laddie and Couper Sandy, in the series Life Among my Ain Folk (1875), show the harsh consequences of economic and social change for cottars, labourers and small tenant farmers.

It deals with burgh politics in the city of Greyness (a thinly disguised Aberdeen) from the 1840s to the 1870s, casting a jaundiced eye on the Victorian ideal of Civic Virtue.