For what group did Bruce Springsteen and his band open a pair of shows at Madison Square Garden in 1978 ?

Southside Johnny and the Asbury Jukes, perhaps?

Nope ! A huge group at the time, whose name also reflects where they first began playing

NEVERMIND ! I went back and realized that I had misread my own scribbled horrible handwriting and the year is 1973

That being said, the concerts were as the opening act for Chicago.

(My apologies for my stupidity)

No problem! I was just surprised that as the year (1978) was SO late, Bruce wouldn't have been opening for anyone other than someone he genuinely wanted to support. All the best though!