Albert Moore Spear was born in Madison, Maine on March 17, 1852 but moved with his parents to Litchfield when only an infant.
Educated in the public schools of West Gardiner, at Monmouth Academy and at Coburn Classical Institute, he graduated from Bates College in Lewiston in 1875. Studying law with Albert R. Savage, a future Chief Justice of the Maine Supreme Court, he was admitted to the bar in 1878.
Opening a law office in Hallowell in 1879 he practiced there until 1885 when he moved to Gardiner. In Hallowell he had severed for six years as City Solicitor and for seven years on the Board of Education, as well as representing that town in the Legislature from 1883 to 1886.
In Gardiner he became the Mayor in a few short years and was, while a resident of that city, elected as Senator from Kennebec County both in 1891 and 1893, serving the latter term as President of the Senate.
Appointed an Associate Justice of the Maine Supreme Court in March of 1902 he continued to serve in that capacity for more than 20 years.
In 1923 Judge Spear retired from active service on the Bench but at the age of seventy-one, at his own request, he was appointed an Active Retired Justice and heard cases throughout the State.
He died at Augusta on January 31, 1929.