Andrew Archibald Macdonald, eldest son of Hugh Macdonald (1788-1857) and Catherine Kennedy Macdonald (ca. 1795-1872), was born 14 February 1829 at Panmure Island, Prince Edward Island. Andrew Archibald married Elizabeth Lee Owen (11 May 1835 - 12 July 1901) on 25 November 1863 in Georgetown. The couple had four children: Aeneas Adolphus MacDonald (20 November 1864 - 1920), Archibald T. G. “Percy” MacDonald (15 April 1867 - 7 November 1948), Reginald Hugh MacDonald (2 September 1869 - 1903?), and A. Douglas MacDonald (1874 - 1921).

Andrew Archibald was educated by private tutors at home and public school in Georgetown. In 1844, at the age of fifteen, Andrew A. entered into business with his cousin, James Macdonald, at James' store in Georgetown. Following his death in 1851, Andrew A. bought the business and brought his brothers Archibald John and Augustine ""Austin"" Colin into the partnership under the name A. A. Macdonald and Bros. For the next twenty years, Andrew A. and his brothers carried on a general mercantile business, importing manufactured goods for sale at their stores in Georgetown and Montague Bridge and exporting grain, potatoes, and lumber to New England, Newfoundland, and Great Britain. The firm was also involved in shipbuilding and the mackerel fishery during this period.

Andrew A. held a number of prominent positions. He served as the United States Consular Agent at Three Rivers from 1849 to 1870. Andrew A. was a longtime member of the House of Assembly, serving as a representative for Georgetown from 1854 to 1870 and was a member of the Executive Council from 1867 to 1873. Andrew A. was a delegate for Prince Edward Island at both the Charlottetown Conference (September 1864) and the Quebec Conference (October 1864). His personal notes and commentary on Confederation and conference proceedings would later be published in a variety of formats. Around 1871, Andrew A. withdrew from A. A. Macdonald & Bros. and moved to Charlottetown. In 1873 Andrew A. was made Postmaster General and retained that portfolio until 1884. In that year he was appointed Lieutenant Governor of Prince Edward Island, a position he held until 1889. On 11 May 1891 he was appointed to the Canadian Senate. From this point on, Andrew A. would divide his time between Prince Edward Island and Ottawa, Ontario. He died in Ottawa 21 March 1912.