Not always but frequently.  Especially to close friends.

I'm about 15 years younger than I think these folks are. Just based on
dress, hairstyles, ... I figure these are high school seniors some time
between the end of WWII and 1955; could be as late as 1960, but I didn't
see a single duck tail amongst the boys & there should be at least one
James Dean wannabe if it's after 1955 ...

When I was in public school (1955 - 1967), you got a school photograph
every year. Somewhere in a shoe box in my mom's attic are dozens of
school photographs, 12 each for myself and my siblings.

The photographer came around to every school in the city and took
everyone's picture. Sometimes only a single shot, other times maybe 2 -
3 (face on & 45 deg left or right). I think it was a long-roll 70 mm
film camera.

     http://www.valdatta.com/camerz.htm

Two light setup, main at 45 deg & fill behind the camera, both with
umbrellas and a roll of seamless paper for the backdrop.

It was like new cars rolling down the assembly line. Your class was
scheduled a certain day and a certain period. If you weren't there that
day, you didn't get your picture taken. Later, they had makeup days for
everyone who was absent the day their class was processed through.

A couple weeks later an envelope of "proofs" came back along with an
order form. Proofs were just a print that had not been fixed, wouldn't
fade if kept in the envelope, but you couldn't display it because it
would fade.

From the proofs you selected the print you wanted and a package of
prints, usually 1-8x10, 2-5x7s and a bunch of "wallet size", pretty much
what could be printed on some multiple of whole 8x10 papers. Package
prices ranged from $3 - $10 and

We didn't have yearbooks until I reached high school, but it was the
same photographer and the yearbook photo came from the same session.

When I reached high school, the freshmen and sophomores were
photographed by "homeroom" for the yearbook. All of you lined up on the
steps in rows. If you were absent that day you weren't in the yearbook,
although there was a makeup day when you could get your individual
portrait done so mama & daddy could buy a package.

Juniors and seniors had individual photographs in the book.

High school yearbooks were common in North Carolina at least as early as
the 1930s. A few years back I found an old yearbook senior year (1940)
yearbook from my Dad's high school at a flea market. I bought it for my
aunt because his family couldn't afford to buy the yearbooks back when
he graduated, coming off the depression then.

Anyway, this is a kind of long winded way of saying I think the custom
was to have both a yearbook and photos for the kids to exchange with
friends and classmates.

So I think it's likely there's a yearbook. And if you're lucky, those
photos are from their senior year, and you could match the photographs
you have in your box with the photographs in the yearbook.