...State constitutions protecting voting rights for blacks
included those of Delaware (1776), 
Maryland (1776), 
New Hampshire (1784), 
and New York (1777). 
(Constitution signer Rufus King declared that in New York, “a citizen of color was entitled to all the privileges of a citizen. . . . [and] entitled to vote.”) 
Pennsylvania also extended such rights in her 1776 constitution, 
as did Massachusetts in her 1780 constitution.
In fact, nearly a century later in 1874, US Rep. Robert Brown Elliott (a black Republican from SC) queried: “When did Massachusetts sully her proud record by placing on her statute-book any law which admitted to the ballot the white man and shut out the black man? She has never done it; she will not do it.” 
As a result of these provisions, early American towns such as Baltimore had more blacks than whites voting in elections; 
and when the proposed US Constitution was placed before citizens in 1787 and 1788, it was ratified by both black and white voters in a number of States. 
This is not to imply that all blacks were allowed to vote; free blacks could vote (except in South Carolina)...