Complex sentence: History would be made by Nerysoo again when he was elected on October 19,1989 as the first Aboriginal Speaker of the Assembly, and served in that role until November 13,1991.
Split into simpler sentences: History would be made by Nerysoo again when he was elected to be the first Aboriginal Speaker of the Assembly. He would be elected Speaker on October 19,1989 and serve in that role until November 13,1991.