LDS History, 17 Mar. 1839

-- 17 Mar. 1839
[Lucy Mack Smith] Brigham Young presides at a conference at Quincy, Illinois. George Hinkle, Sampson Avard, John Corrill, Reed Peck, W. W. Phelps, Frederick G. Williams, Thomas B. Marsh, Burr Riggs, and others are excommunicated. (1)
-- March 17, 1839
[Quorum of the Twelve] Thomas B. Marsh excommunicated. (2)
-- 1839, March 20-25
Joseph Smith still imprisoned in Liberty Jail, wrote epistle to Saints (D&C 121, 122, 123). (3)
-- 1839 20-25 March
Joseph Smith wrote epistle to Saints from Liberty Jail (D&C 121-23). (4)
-- March 20, 1839
[Joseph Smith] Liberty, Missouri. From jail Joseph Smith dictated a letter to the Saints who had found refuge in Quincy, Illinois, and elsewhere, after they had been driven from Missouri. The letter included what is now known as Doctrine & Covenants 121, 122, and 123. (5)
-- 1839 March 20
[Joseph Smith] Commenced writing epistle from jail to exiled Latter-day Saints, Liberty. (6)
-- 1839, March 20
[Joseph Smith] (age 33)From Liberty Jail, writes an epistle to the Saints, portions of which are later canonized in Doctrine and Covenants 121, 122, and 123. (7)
-- March 21, 1839
[Joseph Smith] Liberty, Missouri. Joseph Smith wrote a letter to his wife, Emma Smith, living in Quincy, Illinois. (5)
-- March 22, 1839
[Joseph Smith] Liberty, Missouri. Joseph Smith sent a letter to landowner Isaac Galland informing him of the Churchs desire to purchase land in the Commerce, Illinois, vicinity, thus saving the Church from fragmentation. (5)
-- 25 Mar. 1839
[Lucy Mack Smith] Howard Coray and other members of his family are baptized in Pike County, Illinois. (1)
-- During 1839 Mar
[Lucy Mack Smith] Revelations received in Liberty Jail (D&C 121, 122, and 123). (8)
-- April 4, 1839
[Joseph Smith] Liberty, Missouri. Joseph Smith wrote a letter to his wife, Emma Smith, from Liberty Jail. (5)
-- April 6, 1839
[Joseph Smith] Liberty, Missouri. Joseph Smith was sent with other prisoners by a dangerous route from Liberty to Gallatin, Daviess County. (5)

Footnotes:
1 - Lucy's Book: A Critical Edition of Lucy Mack Smith's Family Memoir, Edited by Lavina Fielding Anderson, 2001, Signature Books
2 - http://en.wikipedia.org/wiki/Chronology_of_the_Quorum_of_the_Twelve_Apostles_(LDS_Church)
3 - Encyclopedia of Mormonism, Vol. 4, Appendix 2: A Chronology of Church History
4 - http://www.lds.net/forums/scripture-study-forum/12108-church-chronology-1800-2000-part-1-a.html#post214550
5 - BYU Studies Journal, volume 46, no. 4: A Chronology of the Life of Joseph Smith
6 - Joseph Smith Papers: Chronology for the Years 1832-1839
7 - Teachings of Presidents of the Church: Joseph Smith, The Church of Jesus Christ of Latter-day Saints, Salt Lake City, Utah
8 - History of Joseph Smith by His Mother: Revised and Enhanced by Scot Facer Proctor Maurine Jensen Proctor