Actually, Baltimore Friendship Airport became Baltimore-Washington International Airport in 1973, a year after the state bought it from Baltimore City, And PeopleExpress didn't start up until 1981.Yes Peoples Express did do a number on Amtrak. PE could not get slot at DCA so used BAL ( Later changed to BWI to compete with Dulls international name). Flights flew from 9000 ft to 12,000 feet. Altitudes better known as Indian country (Navaho, Cherokee, Apache ). Remember that was the time of dying GG-1s and E-60 speed limits.
The EWR terminal was the original trans Atlantic terminal . When first new terminal built changed name to Marine terminal. Used by EAL shuttle. Not sure when PE used it.
I flew home via Baltimore for a college vacation during my freshman year due to a family event in Baltimore. I had always though the Airport was called "Friendship Airport" and I was a little surprised to find that the name had changed.