Why did actors in old American movies speak formal English and nearly British accents?

It wasn't just movies -- it's all entertainment and higher classes of society (or those looking to join a higher class of society.)

They took elocution lessons and were taught to speak perfect pronunciation which, most of the time, had a bit of an English lilt to it. I tend to think of it not as an English accent, but more of a 'society' accent. (i.e. Katherine Hepburn)

As for the accents in the ‘30s and ’40s, I have a couple of theories. First, many British actors fled to Hollywood in the ‘30s because their voices were very good and the money was better in Hollywood.

Also, many early sound actors came from the Broadway stage, and Broadway actors often tried to speak in what was known as a “mid-Atlantic” accent, ie. (like half-way between London and New York), an accent that was half-British and half US Northeastern upper crust English, as with old wealthy families of the Northeast. I heard an acting coach (a black guy) telling a reporter that that’s the style his school still tries to teach to young New York actors.

Back then, movies were trying to be sure they could be understood across the country... America is a big place... with lots of accents... and things were still more regional then... so all people were not always familiar with all the different accents... so a generic "proper" language made sense... Proper English language has almost the same rules on either side of the ocean... only the accents are different... and nowadays, people don't even TRY to speak properly... they are too busy being hip & cool & keeping it real...

Because most of them were real actors with years of formal training many of them came from acting at theaters. Quality in acting and proper use of language was a very important back there, not like today were any illiterate moron can get an acting job based only on his/her abs and good looks.

And by the way many great actors of that time like Cary Grant were British actors that moved to America and they learned to make their accent less noticeable.

Because that's the way Americans really used to talk. Only after the invention of television were Americans introduced to country-wide slang and speech. Before television/movies you only knew of the speech patterns around you, in your own invironment. After tv/movies, you could see that people in different areas of the country actually DID speak with different tones and pronunciations. So in a movie from, say 1940, before television, a Tennessee hick may have sounded like a British royale. Then when people 'learned' about others cultural accents, someone from Tennessee actually sounded like someone from Tennessee. I hope I'm not being too confusing :-) great question though!

I think there are two reasons.

To Americans, the British accent means class and sophistication. When movies were first being made, they had to make a claim for legitamacy, because a lot of people in the early days of movies thought acting lead to immorality.

The other reason is, if you want to earn the respect of fellow actors, it pays to be "classically trained" in acting. To most Americans, this means, trained in Shakespeare and in the British school of arts.

Proper American English is, in most instances, a thing of the past unfortunately. It would be wonderful if we still spoke that way.

Most of the actors in motion pictures had backgrounds in theater....And in theater especially Shakespearean theater

diction and correct pronunciation were essential..

In fact most people that went to the movies back then "dressed up"....The atmosphere was almost like being in a theater.....I myself remember when people would stand and applaud at the end of a good movie...

Kinda stupid when you look back at it.

Because they wanted to sound smart and cool... haha like James Bond

I just think they did it to be more dramatic.