From their impressive record of seven championships in a 10-year span beginning in their first year of existence to “The Kardiac Kids” and “Dawg Pound” years through the franchise’s rebirth in 1999, the Pro Football Hall of Fame will celebrate the rich history of the Cleveland Browns with a temporary exhibit titled, “A Legacy Unleashed.” The new, multi-area exhibit will open to the public at 9 a.m. March 15 and is scheduled to run daily through April 21.