How was democracy in the US expanded during the Reconstruction Era?

During the Reconstruction Era, democracy in the U.S. was expanded primarily through the passage of the 13th, 14th, and 15th Amendments. The 13th Amendment abolished slavery, while the 14th granted citizenship and equal protection under the law to all persons born or naturalized in the U.S., including former slaves. The 15th Amendment prohibited denying the right to vote based on race, thereby enfranchising African American men. These legal changes aimed to integrate formerly enslaved individuals into the political system and promote greater equality.