Lincoln was collecting evidence for lawsuits on behalf of the Alton and Sangamon Railroad Company, which had retained Martin and Lincoln & Herndon to collect balances due on shares of capital stock purchased by stockholders.

The Illinois General Assembly chartered the railroad in February 1847 to construct and operate a railroad between Alton, Illinois, via New Berlin, and Springfield, Illinois. Section two of the company’s charter allowed the incorporators to issue $500,000 in stock at $100 per share, and section six required subscribers to purchase stock by paying $5 on each share subscribed at the time of subscribing and the balance in installments called for by a board of directors. The incorporators opened subscription for stock in May 1847. Many stock subscribers owned property near the proposed route. On January 29, 1851, however, the General Assembly altered the charter to allow the company to construct the road on a more direct route, bypassing the property of several stockholders. Believing that the change in route voided their subscription agreements, many investors refused to pay their remaining installments, and the company hired Lincoln & Herndon to collect the full subscriptions. Several of the delinquent subscribers were from Sangamon County, Illinois, and thirty-seven were from Madison County, Illinois. The railroad hired Martin to collect the full subscriptions in Madison County and Lincoln & Herndon to collect in Sangamon County. In addition to being an attorney for the railroad, Martin was also one of the original incorporators.

Lincoln planned to bring suit on behalf of the railroad against Sangamon County residents James A. Barret, Joseph Klein, Sr., John M. Burkhardt, and Thomas J. Kirkpatrick. Burkhardt and Kirkpatrick paid their installments, and the railroad dismissed their cases against them. Lincoln continued to pursue cases against Barret and Klein.

The “New York depositions” came from Isaac Gibson, secretary of the railroad. Lincoln hoped to depose Gibson in the Barret and Klein lawsuits. On February 26, 1851, Lincoln wrote Gibson, requesting that he bring the books of the corporation and appear before the Sangamon County Circuit Court at the opening of its spring session on March 17. Gibson responded to this letter on March 15 with a telegram and a letter, relating that it would be impossible for him to appear before the court in March 1851, forcing Lincoln to postpone the suits against Barret and Klein until the August term. Gibson gave his deposition in August 1851 in New York City.

Lincoln was particularly keen to obtain evidence that the railroad had given proper notice in calling for stockholders to pay their installments. Section fourteen of the railroad’s charter required the directors to give notice of the payments required at least ninety days prior to date of payment, in newspapers in the locations where notice for opening the books for subscriptions had been published. St. Louis, Springfield, and Alton were the cities where the incorporators published notices for subscriptions. The case files include handwritten transcriptions of calls for installments from the Alton Telegraph & Democratic Review and the Illinois Journal, but this did not satisfy Lincoln; he was eager to find proof of the railroad’s calls in the newspapers themselves, particularly Springfield’s papers, and in a letter to Martin dated August 29, he expressed frustration with this effort.

In addition to this letter and the aforementioned letter of August 29, Lincoln wrote Martin nine other letters on these cases.