Why do we make our cars so small?

My uncle collects 100's of classic cars, he picks me up in a different one everyday since my parents work. Tomorrow he is picking me up in his 1951 Hudson Hornet. But when I look at the modern cars compared to the one I'm in, I always wonder why we make them so small. I mean, I'm 15yrs old, a boy and I'm a car nut, I take pictures of every classic car I see, even if its my uncle driving! But the smallest car he has is the Ford Model A. But why does GM make their car smaller? (GM owns GMC, Buick, Chevrolet, and Cadillac). But why do we make our cars smaller even though America was known for their big cars.

Added (1). I live in the San Francisco Bay, California

Cheaper to make, more comfortable and handle better, better on gas.

American cars are still bigger on average than cars in most other countries.

Why did we make them smaller? Parking. Fuel efficiency. Cost.

For people who want a big vehicle, they go to the large SUV market. A GMC Denali is just a few inches shorter than a Hudson Hornet, and it has much more space inside.

The Denali also has more than twice the horsepower than the Hornet did when it was new.

Because Small is Beautiful.

People don't want to have to pay for things they don't need. If this happens to be a huge car, then it means they won't buy a huge car. Since most people don't have a need for a huge car, companies made lots of smaller cars to fit the demands of people.
there are still some big cars out there for those that do need the space but for the most part, people don't.

Cars got smaller in the 70's when the oil crisis hit. Suddenly the government mandated all car manufacturers to adhere to fuel economy standards. Ever since then the manufacturers made cars smaller and more fuel efficient, while trying not to sacrifice power.

Manufacturers are still allowed to have big vehicles that uses a lot of gas, but it has to be offset by a smaller really fuel efficient one. Aston Martin is a good example of this. Their cars are mostly V8's and V12's, but since they made the Aston Martin Cygnet(a smart car version of aston martin), they still met emission and fuel efficiency standards.

Cause they're cheaper. Cheaper to build, cheaper to own (smaller engine + lighter car= less gas). It's not complicated.

Hi small cars are less expensive to own and run.

That hornet was an unusual car even for its time. It had a frame that went around the passenger compartment instead of under it The result was that you actually stepped down into it. The center of gravity was so low that the car was almost impossible to roll. In spite of all that it had an amazing amount of space and headroom in the passenger compartment.

I agree, the auto makers would benefit from looking again at some of the older models.