And so did the US flag until just a few decades before... and sort of right up until Emancipation. Some northern US states didn't outright ban slavery until Emancipation. They just banned the importation of new slaves and ended the practice of generational slavery, with slave owners keeping their existing slaves for life, but children born of them would be emancipated upon reaching adulthood. Several northern US states still had slaves at the start of the Civil War. All 13 of the original colonies engaged in slavery and all continued the practice for years or even decades after 1776. Slavery in the US started and continued for decades under the US flag.
From Google AI:
Although many northern states had abolished slavery by 1860, some Union-loyal border states and territories still legally held enslaved people. A total of
451,021 enslaved people lived in these Union areas at the time of the 1860 census.
The institution of slavery was far more complex in the North than the "free vs. slave" perception suggests. Here are key details:
- Border states and territories: The majority of the enslaved population in Union-controlled areas was in the border states of Maryland, Delaware, Kentucky, and Missouri, and in some territories. The Emancipation Proclamation in 1863 did not apply to these Union-loyal slave states.
- New Jersey: Due to a gradual emancipation law passed in 1804, New Jersey was the last northern state to formally abolish slavery. In 1860, 43 people were still listed as enslaved in the state, according to the census.
- Gradual abolition: Many northern states passed gradual abolition laws in the late 18th and early 19th centuries, but these laws did not immediately free all enslaved people. For instance, children born to enslaved mothers had to serve for many years before being freed. It took decades for slavery to be completely phased out.
- National economy: Even after formally outlawing slavery, many northern businesses, particularly textile mills, profited from the slave labor system of the South.