The British Concord Expedition: The Problem of Numbers
No official count of troop strength has been found for this mission. Estimates by participants and eyewitnesses ranged between 600 and 900 men. Barker thought it numbered “about 600 men”; an officer of the 59th Foot, “600 men including officers”; Evelyn, “near 700”; an anonymous light infantryman, precisely 756; and Richard Pope, “nearly 800 men.” One observer, Boston printer John Boyle, counted “about 900 Regular troops, but his estimate has been rejected by all historians of the battle as too high. Cf. John Boyle, “Boyles Journal of Occurrences in Boston, 1759-1778,” NEHGR 85 (1931) 8.
The estimates of historians have tended to vary according to their politics. In general, the more Whiggish the scholar, the larger his estimate of British numbers; the more Tory or Anglophile, the smaller the force becomes. The Whig historian Gordon reckoned the force at “800 men or better.” Bancroft, Coburn, Frothingham, Hale, Hudson, Lossing, and Shattuck were content with 800. Robert Gross preferred “seven to eight hundred.” French, Tourtellot, and Galvin reckoned “in the neighborhood of 700.” The American Anglophile Harold Murdock extrapolated from average company strength of the 23rd Foot (28.2 men) to a controlled guess of 588 rank and file.
These estimates derive mainly from impressions of contemporaries, and the conventional judgments of other scholars, and in the case of Murdock from a strength report for a single regiment, drawn from the diary of Frederick Mackenzie.
Monthly strength reports for all units engaged at Lexington and Concord are missing in the Public Record Office, but another source helps to settle the question. Regimental rosters and paylists are available for the 1774-75. Each regiment submitted twice a year a roster, sworn before a magistrate and witnesses. These documents were meticulously compiled in elaborate detail. A separate folio sheet was prepared for each company, listing by name and rank every man who had served in the unit since the last report, with dates of duty, promotions, transfers, leaves, desertions, discharges, detached duty, etc. The Boston regiments in general submitted reports in the winter of 1774—75, and again in the summer of 1775. These documents were not snapshots, but moving pictures. They are imperfect in some details. Men who were relieved from duty for sickness or wounds or special assignments were listed only for the end of the reporting period, but not for other dates. Other movements are noted throughout the reporting period. These records reported an extraordinarily high rate of turnover. Men were frequently transferred in and out of individual companies, commonly from other units in the same regiment. Recruits and replacements arrived throughout the period.
No rosters were found for the British Marines before 1777. By the beginning of that year, the “American battalion” that had served at Boston had moved to Halifax. Its grenadier company had a strength of 3 officers and 29 men. Its light infantry company (the same that marched to Concord) was very much larger, with 117 other ranks; but it is not clear that the company was of similar size in April, 1775. Another method of estimation was used here to avoid an overcount. The total strength of the British Marine battalion in Boston was reported by its commander Major Percy at 387 effectives, 22 percent larger than the mean effective strength of the army regiments in Boston on April 1, 1775. An estimate for the Marine grenadiers and light infantry companies was added here in the same ratio, as 122% of mean strength in other companies. If the earliest pay rosters are an accurate indicator, the true strength was not 43 but 73 rank and file. The smaller number is used here, as a lower-bound estimate. Contingency men are not included.
These lists indicate the following numbers of “effectives” as of April 18, in the companies that marched to Lexington and Concord:
There may have been as many as seven additional members of Mitchell’s party, and perhaps another 60 Marines, if the 1777 rosters are correct, and Loyalist volunteers, minus one straggler at the Phips farm. The size of the Concord expedition might therefore have been as large as 909 officers and men. If so, the rejected estimate of John Boyle proves to be the most nearly accurate.
Are the muster rolls a trustworthy source? For the 23rd Royal Welch Fusiliers they can be tested against the diary of Frederick Mackenzie, who reported that the number of rank and file under arms on April 19 was precisely the same to the man as the estimate that emerges from the rosters. Gage and Haldimond established elaborate procedures to ensure accurate and honest reports, and were successful.
There is only one possible source of error. These estimates assume that the proportion of men who were ill, absent, on detached duty or otherwise “ineffective” was the same on April 19 as at the date of the preceding roster (circa Jan. 30, 1775). There was some attrition in Gage’s army during the entire period. From January to June, net attrition other than losses in combat totalled only 1.9% for the rank and file in all companies of every marching regiment. A special effort was made to keep up the strength of grenadier and light infantry companies by transfering men from the line companies (Barker, British in Boston, 58-59). Even the mean attrition rate of the garrison as a whole would reduce these estimates by only 15 men. For flank companies, the wastage was smaller, and the net change may actually have been in the opposite direction, as men on detached duty returned to their units when they went on active service.
The sources for these estimates are Regimental Rosters in WO12, PRO. Cf. Barker, British in Boston, 31; W. G. Evelyn to his father, April 23, 1775, Scull, Evelyn, 53; an anonymous light infantryman in Letters on the American Revolution, 187—200; Pope,Late News, entry for April 18, 1775; French, Day of Concord and Lexington, 73; Murdock, The Nineteenth of April, 47; Tourtellot, Lexington and Concord, 104; Gross, Minutemen and Their World, 115.