The Bureau of Labor Statistics has archived record lows and highs by state, and 2018 proved to break the record low in 19 states. 7 of those states broke their record low in December 2018. The lowest unemployment rate was 2.0% in Hawaii for the month of May. These state unemployment rates reflect the national unemployment levels we saw in 2018, which in September reached the lowest point since 1969.
The Local Area Unemployment Statistics report published by the Department of Labor is available here: https://www.bls.gov/web/laus/lauhsthl.htm