I think our lives have shifted focus. Once, we focused on family and community. This was what we centered our lives around because it was all we really had access to. Now, technology gives us the ability to have a more global perspective. Thanks to television media and the Internet, I can know what is happening in foreign nations. Sometimes this broader focus is good. It gives us a different perspective and allows us to share our world with everyone. At other times, this broad focus lacks the sense of comradery and local character we once shared. While almost everyone knows what is going on in Syria and Afghanistan, few people know the names of their neighbors.
The family structure has changed a lot in the past seventy years, largely due to technology. There are more jobs for women, so women are accepted in more fields. There are also more technological gadgets that make less housework, so women can work outside the house. Basically, it is much more common for families to have two breadwinners instead of one, and the economy has necessitated it as well.
Technology was present in people's lives 70 years ago as well. The radio in particular had been around about as long by that point as the personal computer has today. But what has really changed is the ubiquity of technological gadgets, especially the cell phone. Even 20 years ago, if you were driving through the countryside, you were essentially cut off from everything. Not today. You can be constantly connected to the rest of the world almost wherever you go.
At first it was a matter of television beginning to consume so much of our time. For the first time, children began to be "raised" on tv shows (beginning in the 50's and 60's).
Now, the effects of technology are seen in our new "inter-connectedness." Social networking and the cellphone have changed how we relate to each other. They even have political implications. Consider the pictures we see from places like Iran and Syria involving violence and demonstrations. We would never have those a few years ago, before personal communications made it possible.
Seventy years ago, there was still no TV: Radio and movie theatres provided the best forms of entertainment. In the evenings, families sat around the house reading, sewing, playing board games, doing homework and listening to the radio. The advent of TV, video, computers and the Internet has certainly changed family life since then.
Household appliances have changed the way that we organize our day-to-day and week-to-week lives. Reliable refridgerators and freezers have changed the way we shop (how often; how much (quantity);fresh vs. frozen). Microwave ovens have altered the way we cook.
These technologies are not as impacting as those mentioned above, but they are substantial in the way they affect the way we spend our time.
The first answer is right about the kinds of changes that we actually perceive. I'm more interested in the changes that affect our lives but that we don't even think about. So I'll go with the idea that transportation technology has changed our lives more than anything. Because of containerized shipping and huge ships, we get many more cheap goods from all over the world. This has been good for us as consumers, but it has also exposed our manufacturing workers to intense competition. This is stuff that really impacts us to a tremendous degree.
I think the biggest changes have come in the form of telecommunication and computer technology. Imagine a world without phones, Internet, or television and you have entered the time period you described. Seventy years ago most Americans woke up and learned about the world from reading newspapers that are now becoming obsolete. Information is instantaneous, and people are constantly in contact with one another.