-- During 1839
Lorenzo Snow: Taught school in Shakersville, Ohio, 1839-40. (1)
-- 19 May 1840
[Wife of Lorenzo Snow] Birth of Mary Elizabeth Houtz, future wife of Lorenzo Snow (2)
-- During May 1840
Lorenzo Snow: Moved to LaHarpe Illinois, May 1840. (1)
-- July 17, 1840
He was ordained to the office of Seventy on July 17, 1840 by Joseph Young. Lorenzo Snow enjoyed perhaps the shortest tenure in priesthood office in the history of the Church, for on the very next day, July 18, 1840, Don Carlos Smith, younger brother of the Prophet, ordained him a High Priest. (3)
-- Jul 18, 1840
Lorenzo Snow: Ordained high priest 18 July 1840 by Don Carlos Smith. (1)
-- 1840, August 15
Baptism for the Dead publicly announced by Joseph Smith. (4)
Endnotes:
1 - Cook, Lyndon W., The Revelations of the Prophet Joseph Smith: A Historical and Biographical Commentary of the Doctrine and Covenants, Seventy's Mission Bookstore, Provo UT, 1985, http://amzn.to/RevelationsofJosephSmith
2 - http://en.wikipedia.org/wiki/Lorenzo_Snow#Wives_and_children
3 - G.A. Pages, http://gapages.com
4 - Ludlow, Daniel H. editor, Encyclopedia of Mormonism, Macmillan Publishing, Encyclopedia of Mormonism, Vol. 4, Appendix 2: A Chronology of Church History, http://amzn.to/eG0DIp
LDS History Chronology: Lorenzo Snow
Mormon History Timeline: the life of Lorenzo Snow
http://lds-church-history.blogspot.com/