The 15th United States Congress was a meeting of the legislative branch of the United States federal government, consisting of the United States Senate and the United States House of Representatives. It met in the Old Brick Capitol in Washington, D.C. from March 4, 1817, to March 4, 1819, during the first two years of James Monroe's presidency. The apportionment of seats in the House of Representatives was based on the 1810 United States census. Both chambers had a Democratic-Republican majority.

Letter of December 1818 Two major treaties with the United Kingdom were approved, finalized and signed during the 15th Congress, both the Rush–Bagot Treaty and the Treaty of 1818, both of which pertained to the United States-Canada border, and both of which were overwhelmingly popular in the United States. President James Monroe and Secretary of State John Quincy Adams were credited with the accomplishments. A letter signed by many members of congress expressing "Gratitude, amity and brotherhood with Great Britain" was addressed to British Prime Minister Robert Jenkinson, 2nd Earl of Liverpool, British Secretary of State for War and the Colonies Henry Bathurst, 3rd Earl Bathurst, British foreign secretary Robert Stewart, Viscount Castlereagh and Britain's minister plenipotentiary and envoy extraordinaire to the United States Charles Bagot. The letter also attacked King Louis XVIII of France for insulting remarks he had made towards American diplomats and about the United States, as well as his refusal to pay reparations owed to the United States from damages incurred during the Quasi-War. The letter was signed in December 1818 by Joel Abbot, Thomas W. Cobb, Zadock Cook, Joel Crawford, John Forsyth, William Terrell, Charles Tait, William Smith, John Gaillard, Henry Middleton, William Lowndes, James Ervin, Joseph Bellinger, Starling Tucker, Eldred Simkins, Elias Earle, Wilson Nesbitt, Stephen Decatur Miller, Montfort Stokes, Nathaniel Macon, Lemuel Sawyer, Joseph Hunter Bryan, Thomas H. Hall, Jesse Slocumb, James Owen, Weldon Nathaniel Edwards, James Stewart, James Strudwick Smith, Thomas Settle, George Mumford, Daniel Munroe Forney, Felix Walker, Lewis Williams, John J. Crittenden, Isham Talbot, David Trimble, Henry Clay, Richard Mentor Johnson, Joseph Desha, Anthony New, David Walker, George Robertson, Richard Clough Anderson Jr., Tunstall Quarles, Thomas Speed, William Hendricks, James Noble, Waller Taylor, John Eaton, John Williams, John Rhea, William Grainger Blount, Francis Jones, Samuel E. Hogg, Thomas Claiborne, George W.L. Marr, George Poindexter, Prentiss Mellen, Harrison Gray Otis, Enoch Lincoln, Jonathan Mason, Nathaniel Silsbee, Jeremiah Nelson, Timothy Fuller, Elijah H. Mills, Samuel Clesson Allen, Henry Shaw, Zabdiel Sampson, Walter Folger Jr., Marcus Morton, Benjamin Adams, Solomon Strong, Nathaniel Ruggles, John Holmes, Ezekiel Whitman, Benjamin Orr, John Wilson, Thomas Rice, Joshua Gage and Albion Parris, all of whom also voted to ratify both of the aforementioned treaties. Several governors also signed the letter, which was entirely symbolic and intended as a gesture of goodwill, including Gabriel Slaughter, William Rabun, John Geddes, John Branch, John Brooks, James Patton Preston and David Holmes. This was significant because the governors and the members of congress were from different regions (both Massachusetts and several southern states were represented), and because signers came from both the Whig Party and the Democratic-Republicans.The American Response to Canada Since 1776 by Gordon T. StewartJohn Quincy Adams: Policymaker for the Union by James E. Lewis Jr.The Undefended Border: The Myth and the Reality by Charles Perry Stacey, Canadian Historical Association, 1967The American Entente by Robert Balmain Moway pg. 41-45 Many members of congress and Washington DC had a very hostile relationship with France's notoriously combative ambassador Jean-Guillaume, baron Hyde de Neuville, which contributed to the letters contents as per France.America in the French mind during the Bourbon Restoration by John deWitt MacBride 1955 pg. 45-46

Major events

March 4, 1817: James Monroe became President of the United States July 4, 1817: Construction on the Erie Canal began November 20, 1817: The first Seminole War began in Florida January 2, 1819: The Panic of 1819, the first major financial crisis in the United States, began. February 2, 1819: Dartmouth College v. Woodward: Supreme Court allowed Dartmouth to keep its charter and remain a private institution.

Major legislation

April 4, 1818: Flag Act of 1818, Sess. 1, ch. 34,

Treaties April 29, 1817: Rush–Bagot Treaty signed between the U.S. and the United Kingdom October 20, 1818: Treaty of 1818 between the U.S. and the United Kingdom established the northern boundary as the 49th parallel from the Lake of the Woods to the Rocky Mountains, also creating the Northwest Angle. February 22, 1819: Adams-Onís Treaty: Spain ceded Florida to the United States

States admitted and territories created December 10, 1817: Mississippi admitted as the 20th state December 3, 1818: Illinois admitted as the 21st state March 2, 1819: Arkansas Territory was created, ; it was formerly part of the Missouri Territory

Party summary The count below identifies party affiliations at the beginning of the first session of this congress. Changes resulting from subsequent replacements are shown below in the "Changes in membership" section.

Senate During this congress, two Senate seats were added for each of the new states of Mississippi and Illinois.

House of Representatives During this congress, one House seat was added for each of the new states of Mississippi and Illinois.

Leadership

Senate President: Daniel D. Tompkins (DR) President pro tempore: John Gaillard (DR), elected March 4, 1817 James Barbour (DR), elected February 15, 1819

House of Representatives Speaker: Henry Clay (DR)

Members This list is arranged by chamber, then by state. Senators are listed by class and representatives are listed by district.

Skip to House of Representatives, below

Senate

Senators were elected by the state legislatures every two years, with one-third beginning new six-year terms with each Congress. Preceding the names in the list below are Senate class numbers, which indicate the cycle of their election. In this Congress, Class 1 meant their term began in the last Congress, requiring re-election in 1820; Class 2 meant their term began with this Congress, requiring re-election in 1822; and Class 3 meant their term ended with this Congress, requiring re-election in 1818.

Connecticut 1. Samuel W. Dana (F) 3. David Daggett (F)

Delaware 1. Outerbridge Horsey (F) 2. Nicholas Van Dyke (F)

Georgia 2. George Troup (DR), until September 23, 1818 John Forsyth (DR), November 23, 1818 – February 17, 1819 3. Charles Tait (DR)

Illinois 2. Jesse B. Thomas (DR), from December 3, 1818 (newly admitted state) 3. Ninian Edwards (DR), from December 3, 1818 (newly admitted state)

Indiana 1. James Noble (DR) 3. Waller Taylor (DR)

Kentucky 2. John J. Crittenden (DR), until March 3, 1819 3. Isham Talbot (DR)

Louisiana 2. William C. C. Claiborne (DR), died November 23, 1817 Henry Johnson (DR), from January 12, 1818 3. Eligius Fromentin (DR)

Maryland 1. Alexander C. Hanson (F) 3. Robert H. Goldsborough (F)

Massachusetts 1. Eli P. Ashmun (F), until May 10, 1818 Prentiss Mellen (F), from June 5, 1818 2. Harrison Gray Otis (F)

Mississippi 1. Walter Leake (DR), from December 10, 1817 (newly admitted state) 2. Thomas H. Williams (DR), from December 10, 1817 (newly admitted state)

New Hampshire 2. David L. Morril (DR) 3. Jeremiah Mason (F), until June 16, 1817 Clement Storer (DR), from June 27, 1817

New Jersey 1. James J. Wilson (DR) 2. Mahlon Dickerson (DR)

New York 1. Nathan Sanford (DR) 3. Rufus King (F)

North Carolina 2. Montfort Stokes (DR) 3. Nathaniel Macon (DR)

Ohio 1. Benjamin Ruggles (DR) 3. Jeremiah Morrow (DR)

Pennsylvania 1. Jonathan Roberts (DR) 3. Abner Lacock (DR)

Rhode Island 1. William Hunter (F) 2. James Burrill Jr. (F)

South Carolina 2. William Smith (DR) 3. John Gaillard (DR)

Tennessee 1. George W. Campbell (DR), until April 20, 1818 John H. Eaton (DR), from September 5, 1818 2. John Williams (DR)

Vermont 1. Isaac Tichenor (F) 3. Dudley Chase (DR), until November 3, 1817 James Fisk (DR), November 4, 1817 – January 8, 1818 William A. Palmer (DR), from October 20, 1818

Virginia 1. James Barbour (DR) 2. John W. Eppes (DR)

House of Representatives

The names of representatives are preceded by their district numbers.

Connecticut All representatives were elected statewide on a general ticket. . Uriel Holmes (F), until 1818 Sylvester Gilbert (DR), from November 16, 1818 . Ebenezer Huntington (F) . Jonathan O. Moseley (F) . Timothy Pitkin (F) . Samuel B. Sherwood (F) . Nathaniel Terry (F) . Thomas S. Williams (F)

Delaware Both representatives were elected statewide on a general ticket. . Willard Hall (DR) . Louis McLane (F)

Georgia All representatives were elected statewide on a general ticket. . Joel Abbot (DR) . Thomas W. Cobb (DR) . Zadock Cook (DR) . Joel Crawford (DR) . John Forsyth (DR), until November 23, 1818 Robert R. Reid (DR), from February 18, 1819 . William Terrell (DR)

Illinois . John McLean (DR), from December 3, 1818 (newly admitted state)

Indiana . William Hendricks (DR)

Kentucky . David Trimble (DR) . Henry Clay (DR) . Richard Mentor Johnson (DR) . Joseph Desha (DR) . Anthony New (DR) . David Walker (DR) . George Robertson (DR) . Richard C. Anderson Jr. (DR) . Tunstal Quarles (DR) . Thomas Speed (DR)

Louisiana . Thomas B. Robertson (DR), until April 20, 1818 Thomas Butler (DR), from November 16, 1818

Maryland The 5th district was a plural district with two representatives. . Philip Stuart (F) . John C. Herbert (F) . George Peter (F) . Samuel Ringgold (DR) . Peter Little (DR) . Samuel Smith (DR) . Philip Reed (DR) . Thomas Culbreth (DR) . Thomas Bayly (F)

Massachusetts . Jonathan Mason (F) . Nathaniel Silsbee (DR) . Jeremiah Nelson (F) . Timothy Fuller (DR) . Elijah H. Mills (F) . Samuel C. Allen (F) . Henry Shaw (DR) . Zabdiel Sampson (DR) . Walter Folger Jr. (DR) . Marcus Morton (DR) . Benjamin Adams (F) . Solomon Strong (F) . Nathaniel Ruggles (F) . John Holmes (DR) . Ezekiel Whitman (F) . Benjamin Orr (F) . John Wilson (F) . Thomas Rice (F) . Joshua Gage (DR) . Albion K. Parris (DR), until February 3, 1818 Enoch Lincoln (DR), from November 4, 1818

Mississippi . George Poindexter (DR), from December 10, 1817

New Hampshire All representatives were elected statewide on a general ticket. . Josiah Butler (DR) . Clifton Clagett (DR) . Salma Hale (DR) . Arthur Livermore (DR) . John F. Parrott (DR) . Nathaniel Upham (DR)

New Jersey All representatives were elected statewide on a general ticket. . Ephraim Bateman (DR) . Benjamin Bennet (DR) . Joseph Bloomfield (DR) . Charles Kinsey (DR) . John Linn (DR) . Henry Southard (DR)

New York There were six plural districts, the 1st, 2nd, 12th, 15th, 20th & 21st, each had two representatives. . Tredwell Scudder (DR) . George Townsend (DR) . William Irving (DR) . Peter H. Wendover (DR) . Caleb Tompkins (DR) . James Tallmadge Jr. (DR), from December 1, 1817 . Philip J. Schuyler (F) . James W. Wilkin (DR) . Josiah Hasbrouck (DR) . Dorrance Kirtland (DR) . Rensselaer Westerlo (F) . John P. Cushman (F) . John W. Taylor (DR) . John Palmer (DR) . John Savage (DR) . Thomas Lawyer (DR) . John Herkimer (DR) . John R. Drake (DR) . Isaac Williams Jr. (DR) . Henry R. Storrs (F) . Thomas H. Hubbard (DR) . David A. Ogden (F) . James Porter (DR) . Oliver C. Comstock (DR) . Daniel Cruger (DR) . Benjamin Ellicott (DR) . John C. Spencer (DR)