Amendments and ratification
Congress has sent 33 amendments to the states. Twenty-seven were ratified and six were not. This page holds the date Congress sent each one, the date each state acted, and the date ratification was completed.
The dates are read from the footnotes of the Constitution of the United States: Analysis and Interpretation, printed by the Government Publishing Office, and checked against a later edition of the same book, the National Archives and Congressional Research Service reports. A date a source does not give is left blank and marked. Where two sources disagree, both are shown.
The 27 amendments
16th Amendment
Income tax. Congress proposed it on July 12, 1909. Ratification was completed on February 3, 1913, 1,302 days (3.6 years) later.
- Proposed by Congress
- July 12, 1909 (Senate July 5, 1909; House July 12, 1909)
- Ratified by
- State legislatures
- Ratification completed
- February 3, 1913 (36th state, Delaware, Wyoming, or New Mexico) (48 states in the Union)
- Certified
- February 25, 1913, Secretary of State Philander Knox
- Proposal to completion
- 1,302 days (3.6 years)
The sources differ on the proposal date. The National Archives prints "Passed by Congress July 2, 1909. Ratified February 3, 1913." The Constitution Annotated gives the House vote as July 12, 1909 and the Senate vote as July 5, 1909. This page shows the Constitution Annotated date and keeps the Archives line here.
- Under 9.2
- 9.2 to under 17
- 17 to under 26
- 26 to under 34
- 34 or more
- No figure
A dashed tile means the source lists no ratification by that state: it may not have been a state yet, it may have rejected the amendment, or the source may not mention it. Dates are those of the state legislature; where states acted on the same day the order follows the source's list. 5 states share a date with a neighbour in the order. Each state is one equal square, so a small state is as easy to see as a large one. Shading is in five steps; the value is also written on each tile and in the table.
Data table: The order in which states ratified the 16th Amendment
| State | Place in the order |
|---|---|
| Alabama | 1 |
| Alaska | No figure |
| Arizona | 32 |
| Arkansas | 29 |
| California | 16 |
| Colorado | 21 |
| Connecticut | No figure |
| Delaware | 36 |
| District of Columbia | No figure |
| Florida | No figure |
| Georgia | 8 |
| Hawaii | No figure |
| Idaho | 11 |
| Illinois | 4 |
| Indiana | 15 |
| Iowa | 24 |
| Kansas | 25 |
| Kentucky | 2 |
| Louisiana | 34 |
| Maine | 27 |
| Maryland | 7 |
| Massachusetts | 41 |
| Michigan | 23 |
| Minnesota | 33 |
| Mississippi | 5 |
| Missouri | 26 |
| Montana | 14 |
| Nebraska | 19 |
| Nevada | 17 |
| New Hampshire | 42 |
| New Jersey | 39 |
| New Mexico | 38 |
| New York | 31 |
| North Carolina | 20 |
| North Dakota | 22 |
| Ohio | 10 |
| Oklahoma | 6 |
| Oregon | 12 |
| Pennsylvania | No figure |
| Rhode Island | No figure |
| South Carolina | 3 |
| South Dakota | 18 |
| Tennessee | 28 |
| Texas | 9 |
| Utah | No figure |
| Vermont | 40 |
| Virginia | No figure |
| Washington | 13 |
| West Virginia | 35 |
| Wisconsin | 30 |
| Wyoming | 37 |
Source: GovInfo, Constitution of the United States: Analysis and Interpretation (1992). As of November 2, 2026.
State by state, in the order they ratified
| Order | State | Date | Entry as printed in the source |
|---|---|---|---|
| 1 | Alabama | August 10, 1909 | Alabama, August 10, 1909 |
| 2 | Kentucky | February 8, 1910 | Kentucky, February 8, 1910 |
| 3 | South Carolina | February 19, 1910 | South Carolina, February 19, 1910 |
| 4 | Illinois | March 1, 1910 | Illinois, March 1, 1910 |
| 5 | Mississippi | March 7, 1910 | Mississippi, March 7, 1910 |
| 6 | Oklahoma | March 10, 1910 | Oklahoma, March 10, 1910 |
| 7 | Maryland | April 8, 1910 | Maryland, April 8, 1910 |
| 8 | Georgia | August 3, 1910 | Georgia, August 3, 1910 |
| 9 | Texas | August 16, 1910 | Texas, August 16, 1910 |
| 10 | Ohio | January 19, 1911 | Ohio, January 19, 1911 |
| 11 | Idaho | January 20, 1911 | Idaho, January 20, 1911 |
| 12 | Oregon | January 23, 1911 | Oregon, January 23, 1911 |
| 13 | Washington | January 26, 1911 | Washington, January 26, 1911 |
| 14 | Montana | January 27, 1911 | Montana, January 27, 1911 |
| 15 | Indiana | January 30, 1911 | Indiana, January 30, 1911 |
| 16 | California | January 31, 1911 same day | California, January 31, 1911 |
| 17 | Nevada | January 31, 1911 same day | Nevada, January 31, 1911 |
| 18 | South Dakota | February 1, 1911 | South Dakota, February 1, 1911 |
| 19 | Nebraska | February 9, 1911 | Nebraska, February 9, 1911 |
| 20 | North Carolina | February 11, 1911 | North Carolina, February 11, 1911 |
| 21 | Colorado | February 15, 1911 | Colorado, February 15, 1911 |
| 22 | North Dakota | February 17, 1911 | North Dakota, February 17, 1911 |
| 23 | Michigan | February 23, 1911 | Michigan, February 23, 1911 |
| 24 | Iowa | February 24, 1911 | Iowa, February 24, 1911 |
| 25 | Kansas | March 2, 1911 | Kansas, March 2, 1911 |
| 26 | Missouri | March 16, 1911 | Missouri, March 16, 1911 |
| 27 | Maine | March 31, 1911 | Maine, March 31, 1911 |
| 28 | Tennessee | April 7, 1911 | Tennessee, April 7, 1911 |
| 29 | Arkansas | April 22, 1911 | Arkansas, April 22, 1911 (after having rejected the amendment at the session begun January 9, 1911) |
| 30 | Wisconsin | May 16, 1911 | Wisconsin, May 16, 1911 |
| 31 | New York | July 12, 1911 | New York, July 12, 1911 |
| 32 | Arizona | April 3, 1912 | Arizona, April 3, 1912 |
| 33 | Minnesota | June 11, 1912 | Minnesota, June 11, 1912 |
| 34 | Louisiana | June 28, 1912 | Louisiana, June 28, 1912 |
| 35 | West Virginia | January 31, 1913 | West Virginia, January 31, 1913 |
| 36 | Delaware | February 3, 1913 same day | Delaware, February 3, 1913 |
| 37 | Wyoming | February 3, 1913 same day | Wyoming, February 3, 1913 |
| 38 | New Mexico | February 3, 1913 same day | New Mexico, February 3, 1913 |
| 39 | New Jersey | February 4, 1913 | New Jersey, February 4, 1913 |
| 40 | Vermont | February 19, 1913 | Vermont, February 19, 1913 |
| 41 | Massachusetts | March 4, 1913 | Massachusetts, March 4, 1913 |
| 42 | New Hampshire | March 7, 1913 | New Hampshire, March 7, 1913 (after having rejected the amendment on March 2, 1911) |
42 states are listed. Ratification was complete with the 36th state, of 48 in the Union. A "same day" mark means the source gives the same date for the state before or after it; the order then follows the order in the source's list.
Rejections, withdrawals and other steps
| State | What happened | Date | Source sentence |
|---|---|---|---|
| Arkansas | Rejected | at the session begun January 9, 1911 | Arkansas, April 22, 1911 (after having rejected the amendment at the session begun January 9, 1911) |
| New Hampshire | Rejected | March 2, 1911 | New Hampshire, March 7, 1913 (after having rejected the amendment on March 2, 1911) |
| Connecticut | Rejected | No date in the source | The amendment was rejected (and not subsequently ratified) by Connecticut, Rhode Island, and Utah. |
| Rhode Island | Rejected | No date in the source | The amendment was rejected (and not subsequently ratified) by Connecticut, Rhode Island, and Utah. |
| Utah | Rejected | No date in the source | The amendment was rejected (and not subsequently ratified) by Connecticut, Rhode Island, and Utah. |
A state that rejected an amendment could still ratify it later, and some did. Whether a state could take back its vote is not settled by anything held here; the source records the withdrawals as it prints them.
Where each date for the 16th Amendment comes from
- Proposed. The Sixteenth Amendment was proposed by Congress on July 12, 1909, when it passed the House, 44 Cong. Rec. (61st Cong., 1st Sess.) 4390, 4440, 4441, having previously passed the Senate on July 5. Id., 4121. Source: GovInfo, Constitution of the United States of America: Analysis and Interpretation, 1992 edition, part 7 (Amendments) ↗
- National Archives. Passed by Congress July 2, 1909. Ratified February 3, 1913. Source: National Archives, Constitutional Amendments 11-27 ↗
- Ratification completed. Ratification was completed on February 3, 1913, when the legislature of the thirty-sixth State (Delaware, Wyoming, or New Mexico) approved the amendment, there being then 48 States in the Union. Source: GovInfo, Constitution of the United States of America: Analysis and Interpretation, 1992 edition, part 7 (Amendments) ↗
- Certification. February 25, 1913, Secretary of State Philander Knox. On February 25, 1913, Secretary of State Knox certified that this amendment had become a part of the Constitution. 37 Stat. 1785. Source: GovInfo, Constitution of the United States of America: Analysis and Interpretation, 1992 edition, part 7 (Amendments) ↗
Download this ledger as a spreadsheet (CSV) Cite the 16th Amendment Read the text
Dates: GovInfo, Constitution of the United States of America: Analysis and Interpretation, 1992 edition, part 7 (Amendments) ↗, read again against GovInfo, Constitution of the United States of America: Analysis and Interpretation, 2022 edition, Intro.3 (text layer, second read) ↗. Proposal and completion dates for amendments 11 to 27 are also read from National Archives, Constitutional Amendments 11-27 ↗. Held as of November 2, 2026. File SHA-256: 75d0471bcac18754….