Due to the increase in accessibility to employment and services in nearby Halifax, was facilitated by the construction of provincial Highways 101 and 102 through the town in the 1970s, Sackville experienced a rapid growth in population.

Millwood High originally served the expanding communities of Lower, Middle, and Upper Sackville, Beaverbank, and Lucasville.

As a result, Millwood High saw a substantial decrease in population, which ultimately had a negative impact on many academic offerings and previously flourishing extracurricular activities.

Though Millwood has suffered from these changes, many student groups and teams, notably the Millwood Hockey and Curling teams, continue to enjoy success, having advanced to provincial competition on numerous occasions.

In its final years as a 10-12 school, Millwood employed approximately forty teachers, supplemented by two guidance counsellors, and its administration, and served a student population of about 665.