A. & G. W. Kerr & Co.
The Kerr firm was involved in three legal cases in which Abraham Lincoln was an attorney. In at least one case, he was retained by the firm to recover a debt.
Martha L. Benner and Cullom Davis et al., eds., The Law Practice of Abraham Lincoln: Complete Documentary Edition, 2d edition (Springfield: Illinois Historic Preservation Agency, 2009), http://www.lawpracticeofabrahamlincoln.org.