I voted FORTRAN but it depends on your definition of programming language.

The first 8 (of 10) weeks in my first college engineering class focused on FORTRAN. That was 1977, submit a stack of punch cards and wait for a printout of the code and run, typically available the next day.

The last two weeks of that quarter covered Basic, which we ran interactively on terminals connected to a PDP 11/70.

I do remember 'programming' a TI calculator in high school, but I don't think of that as a language. You could save the program on a magnetic card.

I took some CS classes in college and recall one that used a pseudo-assembly language called Orange. I think it was designed for teaching assembly; I don't recall ever compiling/running a program. I also recall studying COBOL on my own to review some code for my Tau Beta Pi chapter.

A Programming Language at Stevens Institute of Technology back in 1968. Fortran 4 to support the high school's system. My third one was PL/C, Cornell University's version of PL/1. It had compilable comments you could turn on and off and "error correcting", which almost always made it more difficult to debug. The compliler was a project of Electrical Engineering grad students. There was no Computer Science dept. at that time.

I first learned FORTRAN in school (on an IBM mainframe) remember the //SYSIN DD punch cards...
After I get my engineer degree I discovered TEK(tronix) SPS(Signal processing System) BASIC on a DEC PDP 05 machine (two perforated ribbons to load after having entered the bootstrap code in octal using keys) tightly associated with a digital oscilloscope. Then was the miraculous VM-SP system on an IBM 4341. Discovered EXEC2 then REXX. Got a computer flu I never recovered since then...
A foot in the grave but so many marvelous discoveries and souvenirs...

From a (rather very) old timer.

Basic loaded via paper tape on a PDP8/E.

Funny EdGr writes about the Victor4800.
I think we had the 4600 at university in Denmark. The RAM was a matrix of ferrit rings.
A professor got angry when he discovered we used calculator to find perfect numbers running throughout the night :-)
At that time I was also creating a resistor network calculation program on the mainframe using paper punch tape and a printer terminal.

Time has changed since 1970s.

APL. I learned at McGill Univ along with PL/1. APL is still very much alive - you should have it on your list!

I am about to install APLX on Linux. Any advice welcome!

My first was actually MATLAB.

Foxpro was awesome! Very good DBMS with a very good true OO language better than anything MS had. So MS bought it and killed it. I think there was even a Unix version.

It was Basic ( I think it was the GW flavor).

I learned to program in Fortran on the university PDP-whatever, punch cards and all. The Commodore PET did not exist for a couple-three more years. My brother had one of the first PETs - we had a lot of fun with it. So after Fortran came BASIC. After BASIC came 6502 assembly language, then 8080/Z-80 assembly language. Enough prehistory :-)

Autocoder - IBM 704, 1401, 305, 650, 7080 beginning in 1959. I was IBM "bundled" support at USAA Insurance and Kelly AFB San
Antonio.

BASIC on the ZX81 and later on the C64.
Very quickly, I moved on to assembly (ZX81 and then C64)
I used assembly too to extend the BIOS (if anyone is interested how to do that, let me know, I'll tell you)
Then...a whole slew (most of which I forgot): Pascal, Prolog, Java.
Nasty detail about the industry: you always "just dont know that one language they need"...best excuse not to hire you...
Melissa

My first programming language and only formal programming class was PL/1 on the IBM 360 back in the spring of 1975.

Started out in Assembler, later I discovered the Basic language and C language.
Learned that I could write in Basic and C and use Assembler to speed up certain hardware calls.

My first language was CPM, should have stuck with it in my opinion. Went on to assembly and Clipper.