In what year was freedom of speech extended to protect against the acts of state governments

It was extended in 1925. The federal government ruled that the state government had to carry out the freedom of speech clause in the national constitution, and that they could not deny it based on their state constitutions. The case in which this was ruled was called Gitlow Vs. The State of New York. Gitlow published a left-wing newspaper. The ACLU argued for him.