Looking through historical aerial photos at mapjunction.com, it doesn't look like the throat on the Charles River was more park-like before the pike was built.

The stock yards were on the south side of the tracks, where Boston Landing and Stop and Shop are today. The north side of the tracks was about a dozen residential properties (Market St to Portsmouth St) and railyard infrastructure.

West of Market St, the creation of Leo M Birmingham Parkway was probably more damaging than the Pike in terms of the number of properties that were ripped up to create roadway.