The document summarizes key events and changes during the Reconstruction Era following the American Civil War. Some of the major political, social, and economic changes included the abolition of slavery through the 13th Amendment in 1865, the establishment of the Freedmen's Bureau to assist formerly enslaved people, and the ratification of the 14th Amendment in 1868 to grant citizenship and equal protection under the law to all people born in the United States. The timeline also notes several "firsts" for African Americans during Reconstruction, such as Hiram Revels becoming the first black senator in 1870.