Henry Larcom Abbot (August 13, 1831 – October 1, 1927) was a military engineer and career officer in the United States Army. He served in the Union Army during the American Civil War and was appointed brevet brigadier general of volunteers for his contributions in engineering and artillery. In 1866 he received additional brevet appointments as major general of volunteers and brigadier general in the Regular Army. He conducted several scientific studies of the Mississippi River with captain, later Major General Andrew A. Humphreys. After his retirement, Abbot served as a consultant for the locks on the Panama Canal. He was elected a Fellow of the American Academy of Arts and Sciences in 1863.
Military life Abbot attended West Point and graduated second in his class, which included Jeb Stuart and G. W. Custis Lee with a degree in military engineering in 1854. He initially wanted to join the Artillery, but shortly after graduation, a classmate convinced him to choose the Engineers. He was commissioned as a brevet second lieutenant in the U.S. Army on July 1, 1854, second lieutenant on October 2, 1855, and first lieutenant on July 1, 1857.Eicher, John H., and David J. Eicher, Civil War High Commands. Stanford: Stanford University Press, 2001. . p. 97. In 1855, Abbot was assigned to work with Lieutenant Robert Williamson's Pacific Railroad Survey in California and Oregon.
While serving in the Army, Abbot and Captain Andrew Humphreys conducted several scientific studies of the Mississippi River. They most notably studied the Mississippi river's flow starting at the Ohio River and going southward down to its base level at the Gulf of Mexico. They attempted to use several European formulas for stream discharge they had learned at West Point, but came to discover that they were all flawed. They then developed their own formula which ultimately also proved to be faulty as they forgot to account for the roughness of slopes in river canals. Regardless, it influenced the evolution of hydrology and was instrumental in the establishment of a United States Army Engineer School at Fort Totten in New York City.Humphreys and Abbot wrote: Report upon the physics and hydraulics of the Mississippi river : upon the protection of the alluvial region against overflow, and upon the deepening of the mouths: based upon surveys and investigations made under the acts of Congress directing the topographical and hydrographical survey of the delta of the Mississippi river, with such investigations as might lead to determine the most practicable plan for securing it from inundation, and the best mode of deepening the channels at the mouths of the river. Washington, D.C.: Government Printing Office, 1867. .
Civil War At the outbreak of the Civil War, Abbot was assigned to Brigadier General Irvin McDowell's forces and was wounded at the First Battle of Bull Run. He later became a topographical engineer in the Army of the Potomac during the Peninsula Campaign and aide-de-camp to Brig. Gen. Andrew Humphreys. During this campaign he was brevetted major for his service at the siege of Yorktown. On July 18, 1862, Abbot was promoted to captain in the Regular Army and was assigned to the staff of Brig. Gen. John G. Barnard until November 11, 1862. He was then briefly assigned as a Topographical Engineer in the Department of the Gulf. On January 19, 1863, he was appointed colonel of the 1st Connecticut Heavy Artillery but on March 3, 1863, was transferred to the Washington Defenses, where he commanded a brigade.
In May 1864, he was transferred to command the Artillery during the siege of Petersburg. On December 12, 1864, President Abraham Lincoln nominated Abbot for appointment to the grade of brevet brigadier general of volunteers to rank from August 1, 1864, and the U.S. Senate confirmed the appointment on February 20, 1865.Eicher, 2001, p. 738. In December 1864 he was placed in command of all siege artillery in the Army of the Potomac and Army of the James, which were besieging Petersburg. In January 1865, General Alfred H. Terry requested General Abbot accompany his expeditionary force to Fort Fisher. Abbot commanded a provisional brigade of siege artillery during the successful Second Battle of Fort Fisher.
Abbot was mustered out of the volunteer service on September 25, 1865. On January 13, 1866, President Andrew Johnson nominated Abbot for appointment to the grade of brevet major general of volunteers to rank from March 13, 1865, and the U.S. Senate confirmed the appointment on March 12, 1865.Eicher, 2001, p. 710. On July 17, 1866, President Johnson nominated Abbot for appointment to the grade of brevet brigadier general in the Regular Army to rank from March 13, 1865, and the U.S. Senate confirmed the appointment on July 23, 1865.Eicher, 2001, p. 731.
Post-Civil War In the post-war years, Abbot continued to serve in the U.S. Army Engineers. He was promoted to major on November 11, 1865. He was assigned to the command of the engineer battalion at Willet's Point, New York. He created the army's Engineer School of Application there, and served on numerous boards, including the Board on the Use of Iron in Permanent Defenses, the Board of Engineers for Fortifications, the Gun Foundry Board, the Board on Fortifications and Other Defenses, and the Board of Ordnance and Fortifications. Abbot's influence can be seen in many facets of the coast defense systems of the United States of that period, particularly in the submarine mine system, and in the use of seacoast mortars. Abbot advocated the massing of 16 mortars in 4 sets of 4, which would fire simultaneously at the enemy warships. The plan became known as the "Abbot Quad".
After his retirement from the Army, Abbot continued to work as a civil engineer and was employed as a consultant to Comité Technique and Comité Statutaire for the locks on the Panama Canal between 1897 and 1900. He was appointed to the Board of Consulting Engineers by Theodore Roosevelt and served between 1905 and 1906 after the Americans took control of building the canal. He was given the task to prepare plans for canal construction and was able to convince Roosevelt and Secretary of War William Howard Taft to approve a lock canal rather than a sea-level canal. In 1915, he was part of the Panama Canal Slide Committee.Brodhead, Michael J. 2012. "The Panama Canal: Writings of the U. S. Army Corps of Engineers Officers Who Conceived and Built It." Page 3.
Retirement Abbot retired as a colonel on August 13, 1895. On April 23, 1904, he was appointed Brigadier General, U.S.A., retired. He died on October 1, 1927, at Cambridge, Massachusetts and is buried in Mount Auburn Cemetery, Cambridge.
Honors Abbot was a member of the National Academy of Sciences and American Philosophical Society, received an honorary law degree from Harvard University, and became a Fellow of the American Academy of Arts and Sciences in 1863.'Book of Members, 1780-2010: Chapter A'. American Academy of Arts and Sciences. Retrieved March 18, 2011. The Oregon military training center Camp Abbot, Abbot Pass in Clackamas County, Oregon, and Mount Abbot are all his namesake. He is also one of the 158 names of people important to Oregon's history that are painted in the House and Senate chambers of the Oregon State Capitol. His name is in the Senate chamber.
Publications
Abbot, Henry L. "The Present Status of the Panama Canal." Engineering News 40 (October 6, 1898): 210–213. An optimistic view of the progress made by the new French canal company and its plans for future construction. Emphasizes the disadvantages of the proposed Nicaragua route. Published separately by the New York Evening Post Printing House, 1898. Abbot, Henry L. "The New Panama Canal." Forum 26 (November 1898): 343–53. Argues in favor of a Panama canal even though it would be in French hands, and urges Americans to abandon further consideration of a Nicaragua canal. Also printed separately by the Forum Publishing Company, 1898. Reprinted as Senate Document No. 41, 55th Congress, 3d Session, December 21, 1898, and as "General Abbot on the Panama Canal," Engineering Record 39 (January 14, 1899): 137–40. Abbot, Henry L. (?) "The New Panama Canal." Scientific American 80 (February 4, 1899): 73–75. Possibly by Abbot. "The present article is written for the purpose of putting the public in possession of the facts regarding the present status and future prospects of this undertaking." (p. 73) Discusses the French canal company's international Comité Technique, of which Abbot was a member; the Culebra Cut; control of the Chagres River; health concerns; and relationship of the new canal company to the old company. Abbot, Henry L. "Climatology of the Isthmus of Panama, Including the Temperature, Winds, Barometric Pressure, and Precipitation." Monthly Weather Review 27 (May 1899): 198–203. Temperature, barometric pressure, and precipitation tables compiled by the old and new French canal companies. "In tropical regions it is not the excessively high temperatures which increase the difficulties of out-door labor and construction, but those which remain permanently high and are accompanied by great humidity of the air and heavy rainfall . . . . " (p. 201) Rainfall comparable to areas of the United States near the Gulf of Mexico. The Weather Bureau issued, as a separate designated W. B. No. 201, a "slightly modified" (p. 3) version of this article. Abbot, Henry L. "Climatology of the Isthmus of Panama." Monthly Weather Review 27 (July 1899): 302–03. Supplemental to May 1899 article. Updates rainfall figures to 1899. Abbot, Henry L. "Meteorology of Panama." Monthly Weather Review 27 (October 1899): 463. More rainfall and temperature data for 1899. Abbot, Henry L. "Contributions to the Meteorology of Panama." Monthly Weather Review 28 January 1900: 7. Hourly temperatures and barometric pressure at Alhajuela and La Boca, observed by personnel of the New Panama Canal Company, autumn of 1899. Abbot, Henry L. "Rainfall and Drainage in the Upper Chagres River." Monthly Weather Review 28 (June 1900): 243–44. Figures showing that "no fear of a lack of water in the dry season need be entertained with the reserves contemplated by the new French [Panama Canal] company." (p. 244) Abbot, Henry L. "The Best Isthmian Canal." Atlantic Monthly 86 (December 1900): 844–48. "[T]his claim of gain of time by Nicaragua must be relegated to the class of visionary arguments so often advanced to offset the solid merits of the Panama route." (p. 848). Abbot, Henry L. (Communication on "The Present Condition and Prospects of the Panama Canal Works," by James Thomas Ford, pp. 150–70.) Minutes of the Proceedings of the Institution of Civil Engineers (London) 144 (February 1901): 199–202. Regulation of the Chagres River is essential for a canal with locks and dams. Data on the discharge of the river at various locations; estimates of time needed for lockages. Abbot, Henry L. "Present Condition of the Panama Canal." Engineering Magazine 22 (January 1902): 487–92. (Editor's introduction to Abbot's article "International Aspects of the Isthmian Canal," pp. 485–87.) Abbot: there are "only three formidable difficulties": "the cut at the continental divide, regulation of the Chagres River, and the tropical climate." Despite these problems, "Nature has placed on the Isthmus of Panama far fewer obstructions to the construction of a ship canal than on any other possible route between the oceans." (p. 488). Abbot favors use of black laborers and suggests that American capital, not the government, should buy out the French company.