Gradual emancipation (United States)

[4] It specified that Every Negro and Mulatto child born within the State after the passing of the Act (1780) would be free upon reaching age twenty-eight.

[4] Four other Northern states adopted policies to at least gradually abolish slavery: New Hampshire and Massachusetts in 1783, and Connecticut and Rhode Island in 1784.

[3] By 1808, the importation of enslaved people was prohibited (though smuggling continued), and by the 1820s all Northern states enacted laws for either gradual or immediate emancipation.

[6][circular reference] Starting in the early 19th century, the concept of gradual abolition spread from the US to Latin America, where it became known as Freedom of wombs.

Abraham Lincoln proposed an amendment to the Constitution for gradual emancipation in 1861 and 1862, culminating with the Second Message to Congress in December 1862.

Speech of the Hon. B. Gratz Brown , of St. Louis , on the subject of gradual emancipation in Missouri - delivered in the House of Representatives (Missouri) Feb 12, 1857
Abolition of slavery in the various states of the US over time:
Abolition of slavery during or shortly after the American Revolution
The Northwest Ordinance, 1787
Gradual emancipation in New York (starting 1799, ended 1827) and New Jersey (starting 1804, ended by Thirteenth Amendment, 1865)
The Missouri Compromise, 1821
Effective abolition of slavery by Mexican or joint US/British authority
Abolition of slavery by Congressional action, 1861
Abolition of slavery by Congressional action, 1862.
Emancipation Proclamation as originally issued, 1 Jan 1863
Subsequent operation of the Emancipation Proclamation in 1863
Abolition of slavery by state action during the Civil War
Operation of the Emancipation Proclamation in 1864
Operation of the Emancipation Proclamation in 1865
Thirteenth Amendment to the US constitution, 18 Dec 1865
Territory incorporated into the US after the passage of the Thirteenth Amendment