Every year in business past 100 is significant. However, these companies deserve a special shout-out for anniversaries of over 200 years:
325 years: Kenyon's Grist Mill, founded 1696, West Kingston RI 2nd generation
285 years: Lakeside Mills, founded 1736, Spindale NC 4th generation
255 years: Beekman Arms (inn and tavern), founded 1766, Rhinebeck NY
235 years: Howard, Kohn, Sprague & FitzGerald (legal services), founded 1786, Hartford CT
220 years: Sawyer Bentwood (furniture), founded 1801, Whitingham VT
215 years: Ye Olde Pepper Candy Companie, founded 1806, Salem MA 4th generation
205 years: Hodgdon Yachts, founded 1816, East Boothbay ME, 5th generation
205 years: York Water, founded 1816, York PA, public utility