How were babies put to bed in the 70s?

Early!

As DS2 had a misdiagnosed bowel abnormality, he was more comfortable on his front. Even in the big pram, he would insist on lying on his front. I had to keep the hood down so that he could do press-ups and look out the end. When he was 2, he had surgery and after that he could sleep any way he wanted. His brother always slept on his side, right from the start as that was how the midwives put him in the hospital.

Early 70s, lie them on their tummies.

I remember my daughter liked to spreadeagle herself on her tummy with her bum in the air. My son was more of a back sleeper.

Always swaddled in a blanket and on their sides. My own two plus foster babies always the same . I remember my aunt , a midwife , saying never on their backs . Just shows how things change.

My three , always in their side or back. I never felt happy about putting them on their tummies except in the day, on the floor while I was there with them.
The ‘Back yo Sleep’ campaign does seem to have worked. Have you ever noticed on a hot night , how much hotter you feel sleeping on your tummy than on your back or side ?

In 1970 cot deaths averaged 1500 annually.

Thanks to the practice of putting babies to sleep on their backs, the number of cot deaths in England and Wales has fallen to the lowest since records began.

There were 128 sudden infant deaths in 2014, according to provisional data from the Office for National Statistics (ONS).

It’s not a case of ‘how things change’ ??? (crass stupidity) but fact backed by statistics.

Mine were born in the '60s, I can't remember what Dr. Spock said - he was the 'expert' in those days.
Another safety point is not to give the baby a pillow or very soft mattress. And don't fall asleep when breast feeding in your own bed.
I think this applies to very young babies - as they get stronger they can change position themselves.