19th century

In 1820, Maine separated from Massachusetts and entered the Union as the 23rd state as a result of the ratification of the Missouri Compromise.^[106]

Textile mills such as the Boott Mills in Lowell made Massachusetts a leader in the Industrial Revolution in the United States.

During the 19th century, Massachusetts became a national leader in the American Industrial Revolution, with factories around cities such as Lowell and Boston producing textiles and shoes, and factories around Springfield producing tools, paper, and textiles.^[107][108] The economy transformed from one based primarily on agriculture to an industrial one, initially making use of water-power and later the steam engine to power factories. Canals and railroads were used for transporting raw materials and finished goods.^[109] At first, the new industries drew labor from Yankees on nearby subsistence farms, and later relied upon immigrant labor from Europe and Canada.^[110][111]
In the years leading up to the American Civil War, Massachusetts was a center of progressivist and abolitionist activity. Horace Mann made the state's school system a national model.^[112] Henry David Thoreau and Ralph Waldo Emerson made major contributions to American philosophy.^[113] Members of the transcendentalist movement emphasized the importance of the natural world and emotion to humanity.^[113]
Although significant opposition to abolitionism existed early on in Massachusetts, resulting in anti-abolitionist riots between 1835 and 1837,^[114] opposition to slavery gradually increased throughout the next few decades.^[115][116] Abolitionists John Brown and Sojourner Truth lived in Springfield and Northampton, respectively, while Frederick Douglass lived in Boston and Susan B. Anthony in Adams, Massachusetts. The works of such abolitionists contributed to Massachusetts' actions during the Civil War. Massachusetts was the first state to recruit, train, and arm a Black regiment with White officers, the 54th Massachusetts Infantry Regiment.^[117] In 1852, Massachusetts became the first state to pass compulsory education laws.^[118]
Alexander Graham Bell is commonly credited as the inventor of the first practical telephone. On March 10, 1876 at Boston University, he was able to communicate with his assistant Thomas A. Watson in the next room.