Personal correspondence (1851-1914) consists primarily of correspondence sent to Amasa and Mary Richards while residing near Shakopee and Wayzata, Minnesota. Most of the letters to Mary are from members of her family, the Plimpton family of Sturbridge, Massachusetts and a brother and sister in law living in Iowa. The letters detail general family matters, illnesses, births and deaths, reports of farming successes and failures, impressions of the Indian situation in Minnesota during the l860s, and events related to the Civil War. Family members whose letters appear regularly are Mary's sisters, Lizzie, Kate, and Lucinda; her brothers Chester and James; and her sisters in law, Laura Ann Plimpton and Laura W. Stone. Also included are letters (1907-1914) of Amasa and Mary's son, George, of Maple Plain, Minnesota.

The Civil War letters were sent to Mary by her brother, Isaac Plimpton, and Amasa.

Isaac served with the Massachusetts 22nd Regiment and was killed (July 1, 1862) at the Battle of Malvern Hill near Richmond. His letters were written while stationed at Halls Hill, Virginia (December 11, 1861 and January 26, 1862).

Amasa's letters (September 1864-July 1865) relate his service with the Minnesota 11th Regiment at South Tunnel Station outside of Nashville. The early letters describe his trip to Nashville by way of Chicago and Louisville. Confederate guerrilla activity around the railroad and tunnel that his detachment guarded is discussed in several letters. Preparations prior to the Battle of Nashville (December 1864) are described (December 8, 1864) and a later letter (December 21, 1864) relates the defeat of General Hood's Confederate army at Nashville. Richards mentions three brothers named Gorden who were tried for desertion (February 7, 1865), and in other letters refers to two large fires in Minneapolis and Saint Anthony (February 26, 1865) and local citizens' attitudes towards the Union and their good treatment of the Union soldiers (April 27, 1865). A letter sent from Pilot's Knob, Tennessee (May 20, 1865) includes two drawings identified as the stockade and living quarters at South Tunnel. Richards relates his observation of the low morale of returning Confederate soldiers and recounts the large sums of Confederate money these soldiers paid for basic items. The discovery of oil in Hennepin County, specifically near Bassett's Creek, is mentioned (June 18, 1865) and, in his last letter (July 7, 1865), Amasa describes his trip home, his astonishment over the positive reception given by people north of the Ohio River, and the homecoming celebration given in St. Paul.

Includes receipts for payment of toll tax (May 17, 1862), an allotment payment ([1864]), notification of tax refund (March 29, 1876), and for a contract to carry mail from Chaska to Delano (September 10, 1876). Correspondence regards Richards' cancellation of a land deal (July 13, 1864), his offer to sell land to the St. Paul & Pacific Railroad Company (May 21, 1868), and discussion of post office matters (May 29 and August 28, 1878). Two letters (February 20 and February 28, 1899) deal with Richards' appointment as guardian in the will of a relative in Valencia, Spain. Miscellany include an advertising bill from the Northwestern Clothing Hall in Minneapolis (October 1, 1872) and a cure for the bite of a mad dog.

The bulk of the picture postcards were sent to George W. Richards while he worked for the railroad. Also included are a number of postcards sent to Mrs. Minnie Anderson prior to her marriage to George Richards. The postcards contain several black and white photographs of Minnesota landmarks and scenery.