How was Elizabeth Freeman involved in the revolutionary war?

Elizabeth Freeman played an important role in American history.  While we usually think of the northern states as being against slavery, before and after the Revolutionary War, there were plenty of slaves in the north, and Elizabeth Freeman was responsible for the end of slavery in those northern states.  She was born a slave in the state of New York and when she was purchased, became a slave in the state in Massachusetts.  Her hsuband was killed in the Revolutionary War, so she had good reason to be interested in what he had died for.  Her interpretation of the Bill of Rights and the Massachusetts Constitution led her to the conclusion that slavery should not exist in the new country, that the freedoms guaranteed by these documents applied to slaves.  She sued and won her freedom, creating a path for freedom for slaves in the northern states.  I have included one source of information about Elizabeth Freeman, and there are others. One interesting question that might be investigated is whether she took this name because of her freedom or whether her husband took this name because he was fighting for freedom in the Revolutionary War.