Isham, Lincoln & Beale, a law firm co-founded by Abraham Lincoln's son, is succumbing to internal strife and closing its doors after 116 years."This has been a trying experience and one of the most regrettable results I've seen in my life," said Richard Marcus, a well-known labor attorney and partner in the Chicago firm.

He said Friday that partners voted to dissolve their practice two years after a merger with a younger firm that proved "a dismal failure."

The Isham-Lincoln partnership was founded in 1872 by Edward Isham, son of a Vermont Supreme Court justice, and Robert Todd Lincoln, a Harvard-educated lawyer who later became U.S. war secretary and U.S. minister to Great Britain.

The firm's clients have included Commonwealth Edison Co., McDonald's Corp., Tribune Co., Fireman's Fund Corp., CBS Inc. and National Broadcasting Co. Inc. But its financial difficulties became public in 1986, when the conservative firm merged with the younger Reuben & Proctor in what was the largest law firm merger in Chicago history.

The amalgam, which retained the Isham name, initially had 225 attorneys. But by Friday, only 80 were left.