Alabama's slaves were freed by the 13th Amendment in 1865. During the period from1867 to 1874 many African Americans emerged as political leaders in the state. Remember nearly half the population was African American. Some sources including Wikipedia say that many whites were disenfranchised at this time but that 'fact' is disputed by other sources and seems not to have solid documentation.
What is known is that during Reconstruction state legislators ratified a new state constitution that created the states first public school system and expanded women's rights. Public works were also funded constructing roads and railroads.
This period of progress was ended with a new election in 1874. These new elected officials passed legislation that racially segregated schools. By 1901 most African Americans and many poor whites had been disenfranchised by the new constitution.