The History of Horror.

Horror, as a film genre, has been one of the largest and most noteable film genres around. It has been with Cinema almost since film had been popularised. It first came about in the 1890s with the film "Le Manoir du diable",  often credited as the first ever horror film (Though Nosferatu is generally given this prestige)
Horror was also explored in the Japanese cinema with films such as Shinin no Sosei. Frankenstein was first released in 1910, though this was not the version everyone is thinking of and was thought to have been lost.

German Expressionists influenced many film genres, including horror. The Cabinet of Dr. Caligari, Nosferatu and The Golem were all released during this time.

When sound first arrived to the Film industry a rise in Gothic horror occured, with classics such as Dracula and Frankenstein. Many horror classics were released in the 1930s but, due to the second great war, there was a significant lack of films in the 1940s.

In the 1950s, when technology had improved, the concentration on Gothic horror transitioned to more contemporary issues. There was a huge influx in low budget films, generally focusing on outside threats such as UFOs and horrific mutations. Some films, such as Invasion of the Body Snatchers would use the fear of the Cold War to their advantage. Japan, after having been the first country to witness the use of nuclear weaponry first hand, made a number of films representing the horror of the event, such as the world famous Godzilla.

In the 60s, the first ever slasher type film, Psycho, was released. The Masque of the Red Death and The Tomb of Ligeia can be argued to have inspired future horror films to be more graphic in their depiction of gore. The 60s also saw the birth of low budget Gore-Shock films like Two Thousand Maniacs! were, as the genre suggests, more about shocking the audience with insane amounts of gore rather than actually scaring them.

The 70s saw a huge rise in lower budget gore films and more occult themes were now being explored because of the success of Rosemary's Baby. The Exorcist was the first of these kinds of movies. Oddly enough, another genre was emerging, the "Evil Children" genre (which is an especially literal title) saw a number of films released featuring evil children. It also saw the world famous Alien, which was a terrific blend of horror and science fiction.

Gorier slasher movies saw a rise in the 1980s. Many were low budget gore fests and were generally panned by critics, though a lot of them eventually became cult classics, such as the Evil Dead series.

The gory slasher films, like Nightmare on Elm Street, were continued into the 90s. The sequels to these films were fairly successful, however the fans of the originals and the critics generally detested them, finding the films to be lazy cash-ins. While there were some new ideas to the genre, the majority of cinema goers found it stagnent and too full of the same material (Evil killer hunts down dopy teenagers and kills them in particularly nasty ways) and the Science Fiction genre was only benefitting from the increase in special effetcs. As a result the horror genre almost ground to a halt.

To make pull its audience back in and gain their interest once more, horror turned into a living parody of itself. Films such as Scream mocked the genre itself, featuring characters who understood the cliches presented during the films (IE: The Black guy dies first) Whilst this was slightly successful, it was fairly obvious the golden age of film horror was over.

As a result of happening from the 90s, the early 2000s were a relatively quiet time for the genre. Jeepers Creepers was a fairly successful franchise, but it was no Dracula. The Others saw a brief return to the psychological horror genre and soon more and more horror films were being made. Thanks to the success of the Resident Evil video game series (not the films though, they suck) a large interest in Zombie themed movies were released, including the famous 28 Days Later and the infamous Resident Evil film series, which fans of the games generally detested.
Later many remakes of older Gore-fest films, like The Hills Have Eyes, were released. This led to large amounts of "Gore-nography" films being released, such as Saw and Hostel.

Many of the films released closer to 2010 were all remakes of classic horror films. The ones that nearly damned the genre.
It's clear that the horror genre has certainly changed since its first appearence in the 1890s, whether or not it's for better or worse is ultimately up to an individual to decide. It is unarguable, however, that the great films from the 1930s to 70s are gone and that we'll likely never see anything such as them ever again.