The collection includes two letters and their original envelope from Jacob S. Winans to his father Dr. Isaac Winans. Both letters were sent in the same envelope. They were written after Winans's return to Camp Tennally (Tennallytown, Maryland) after serving picket at Great Falls, Virginia from September 9-16, 1861. The letters are dated September 17th and September 18th. The envelope postage was cancelled in Washington, D. C. on September 21, 1861.

The envelope is addressed to Dr. I. Winans in New Brighton, Beaver County, Pennsylvania and has a handwritten note on the back regarding a dozen china coffee saucers.

The letter dated September 17, 1861 covers both sides of a page 5 inches wide and approx. 3 feet long. In this letter, Winans begins by describing his recent picket duty at Great Falls, Virginia where members of the company's command personnel were ill and Winans was required to supervise 25-30 soldiers plus a Sergeant and two Corporals. He then tells his father about the clothing issued to them and notes that he will need new shirts soon. Next follows a commentary on why "Alex" (likely his brother John Alexander Winans) should not go to war. In this section he describes the experience of spending days in the rain during the recent excursion to the Potomac River as an example of the hardships that he feels his brother would not have the constitution to endure. Finally, he talks about some of the other soldiers including Sam Veon, W. Parish (possibly Wm. Parris), and Tom Dimond (likely Tom Dimmond). In this section he discusses the behavior and reliability of those under his command, noting that the most reliable in the field are those whom he did not expect anything of before the war. He also discusses a recent court marshall and a disciplinary issue with a soldier under his command. He closes the letter by thanking his father for the paper.

The letter dated September 18, 1861 is a supplement to the first letter. It covers both sides of a page 4.5 inches wide and 8 inches long. In this letter, Winans states that he has delayed the other letter because of a rumor that the company would be paid. He then notes that they were paid and he received $26.65. He states that a $20 treasury note is enclosed and that he would have sent more but could not obtain paper money. He then says that the company will soon receive improved rifled muskets and that he thinks they will soon head to Virginia. He closes by saying he will send any money he can spare each month.