Atlantic tides much higher at end of the ice age because a frozen Hudson's Bay didn't buffer the swings.

                                                                                                   Hudson's bay at top left

From Science Daily:      One of the most interesting findings of the study, Hill said, was that around 9,000 years ago, as Earth was emerging from its most recent ice age, there was a huge amplification in tides of the western Atlantic Ocean. The tidal ranges were up to three times more extreme than those that exist today, and water would have surged up and down on the East Coast.        "Part of what we found was that there are certain places on Earth where tidal energy gets dissipated at a disproportionately high rate, real hot spots of tidal action," Hill said. "One of these today is Hudson Bay, and it's helping to reduce tidal energies all over the rest of the Atlantic Ocean. But during the last ice age Hudson Bay was closed down and buried in ice, and that caused more extreme tides elsewhere."

Hudson's Bay is like a water
hammer arrestor on the water line.