- August 15, 1869 Oshima Province established with seven districts
- 1872 Census reports 75,830 inhabitants of the province
- July, 1881 Tsugaru District and Fukushima District merged to form Matsumae District, reducing the number of districts to six.
- 1882 Provinces dissolved in Hokkaidō.
- Nussbaum, Louis-Frédéric and Käthe Roth. (2005). Japan encyclopedia. Cambridge: Harvard University Press. ISBN 978-0-674-01753-5; OCLC 58053128