See his Official Letters (ed. by R. A. Brock, 2 vol., 1882-85); biographies by W. Havighurst (1968) and L. Dodson (1932, repr. 1969).
Alexander Spotswood was born in the Tangier Garrison, Morocco, Africa about 1676 to Catharine Maxwell (c. 1638 - December 1709) and her second husband, Dr Robert Spottiswoode (17 September 1637 - 1680), the Chirurgeon to the Garrison. Through his father, Alexander was a grandson of Judge Robert Spottiswoode (1596-1646), a great-grandson of Archbishop John Spottiswoode (1565-1639), and a descendant of King Robert II of Scotland through the 2nd Earls of Crawford ). Alexander's older half-brother (by his mother's first marriage to George Elliott) was Roger Elliott (c. 1655 - 15 May 1714), who became one of the first Governors of Gibraltar. Following the death of Robert Spotswood, his mother married thirdly Reverend Dr. George Mercer, the Garrison's Schoolmaster.
On 20 May 1693, Alexander became an Ensign in the Earl of Bath's Regiment of Foot, and was commissioned in 1698, being promoted to Lieutenant-Colonel in 1703. He was appointed Quartermaster-General of the Duke of Marlborough's army the same year, and was wounded at the Battle of Blenheim the following year.
In 1710, Alexander was appointed Lieutenant Governor of Virginia, under the nominal governorship of George Hamilton, 1st Earl of Orkney. He was the first to occupy the new Governors Mansion, which many citizens thought overly extravagant (its 20th-century reconstruction is now one of the principal landmarks in Colonial Williamsburg). A Tobacco Act requiring the inspection of all tobacco intended for export or for use as legal tender was passed in 1713. The next year, he founded the First Germanna Colony, and regulated trade with native Americans. In 1715, he bought 3229 acres (13 km²) at Germanna.
In 1716 he led the Knights of the Golden Horseshoe Expedition up the Rappahannock River valley and across the Blue Ridge Mountains at Swift Run Gap into the Shenandoah Valley to expedite settlement. The following year saw the foundation of the Second Germanna Colony and the Repeal of regulation of trade with native Americans. A Third Germanna Colony followed in 1719, and Germanna was made the seat of Spotsylvania County the following year.
Between 1716 and 1720, Spotswood built the Tubal Works which had a cold blast charcoal blast furnace and produced pig iron. It remained in operation for about 40 years and is possibly the first successful ironworks in the colonies (although Tinton Falls, NJ-late 1600s is another candidate). Pig iron from Tubal is in the collections of the Fredericksburg (Virginia) Area Museum and the NPS (Spotsylvania Courthouse). Tubal Works iron was exported to England by 1723 . In May of the same year Gov. Drysdale reported to the Lords of Trade that Spotswood was selling "backs and frames for Chumnies, Potts, doggs, frying, stewing, and backing panns" at auction in Williamsburg. Around 1732 he built what may be the first purpose built foundry in the British North American Colonies at Massaponax. This was a double air furnace (usually used to make cannon) and was used to recast pig iron produced at Tubal into final shapes (kettles, andirons, firebacks, etc.). Neither of Spotswood's iron operations were at Germanna. Spotswood was not, as is commonly believed, involved in the Fredericksville Furnace.
It was in the fall of 1718 when Spotswood engaged in a clandestine expedition by privately hiring two sloops, Jane and Ranger, and a number of Royal Navy men to seek out the pirate Blackbeard, or Edward Teach. On 18 November 1718, Lt. Robert Maynard sailed from Hampton, Virginia to Ocracoke Inlet, North Carolina. On 22 November 1718, Maynard and his men defeated Blackbeard and the pirates. On 24 November 1718, two days after Blackbeard's death, Spotswood issued a proclamation at the Assembly in Williamsburg offering reward for any who brought Teach and the other pirates to justice.
A Treaty with the Iroquois was arranged in Albany, New York during 1721. Alexander completed the Governor's palace in 1722, when he was recalled from the lieutenant governorship and replaced by Hugh Drysdale. Throughout his career, Spotswood had maintained an adversarial relationship with the Virginia Council, especially its most prominent member, James Blair. As the Bishop of London's representative in the colony, the President of the College of William and Mary, and a councilman in Virginia's highest legislative body, Blair was arguably the most powerful man in the colony. He successfully orchestrated the recall of three royally appointed governors, including Alexander Spotswood, who entered private life with 80,000 acres (324 km²) in Spotsylvania and three iron furnaces.
Returning to London, he married Elizabeth Butler Brayne in 1724, but was back at the 'Enchanted Castle', Germanna, by 1729. He served as Deputy Postmaster General from 1730 to 1739, and died on 7 June 1740 at Annapolis, Ann Arundel, Maryland (MD).