Acknowledge the Corn

One of the slang sayings that I've run across from the 19th century is "acknowledge the corn" which means to admit the truth, to acknowledge one's own shortcoming or obvious lies, one's mistakes, one's faults or in other words to confess.

A couple of cited sources are:
1840: David Johnson acknowledged the corn, and said that he was drunk. Daily Pennant, St. Louis, July 14
1846: I hope he will give up the argument, or, to use a familiar phrase, acknowledge the corn. Mr. Speight, Mississippi, U.S. Senate, Congressional Globe, January 28
1850: He has not confessed the corn, as the saying is, that he did preach disunion? Mr. Staniy, North Carolina, House of Reps., Congressional Globe