Complex sentence: The Chinese Empire first signed the treaty with Russia on 13 June 1858, next with the United States of America on 18 June 1858, and then United Kingdom on 26 June 1859 and finally France on 27 June 1859.
Split into simpler sentences: The Chinese Empire first signed the treaty with Russia on 13 June 1858. Followed by the United States of America on 18 June 1858, and then United Kingdom on 26 June 1859 and finally France on 27 June 1859.