John F. Tolton records the disbandment of the People's Party and the Liberal's Party on June 30, 1890.
John F. Tolton, journal, June 30, 1891, John F. Tolton journal and reminiscences, 1887-1894, MS 4922, Church History Library
June 30th Last night a rousing Democratic meeting was held in Fields Hall. The speakers being Hon. J.T. Caine, Prof. Paul, and Waldemar Van Cott. Mr. Van Cott said he had always belonged to the minority party in Utah. That said party had contended for the support of polygamy and separation of Church and State. The object having now been accomplished it was proper to disband the People's Party and the Liberals'.