The model railroading hobby has a rich history, and every type of train has it's very own story. Take the O model railroad for example. The O gauge is actually the 0 (zero) gauge and was created to be smaller than Gauge 1. This gauge was created by the train manufacturers due to the fact the smaller scale trains were selling better than the large scale models.
The reason for this was generally space. Many modelers were doing much more than just watching the train go around in circles. They were in fact creating elaborate scenery, and they simply could not do that quite as effectively with the larger trains. In 1929 it became clear that a depression was in the air and as a result the market for larger scale trains went down the drain.
Before the second world war, the sizes of the O model railroad trains varied greatly, but they were all capable of running on the same track. This made them highly compatible and even interchangeable for hobbysists. The O scale was truly setting a standard that many people never expected to see in their lifetime.
Following the second world war when materials were more plentiful these trains suddenly became more realistic than ever before. For the first time they were becoming larger and resembling real world trains. Hobbyists were becoming truly interested now and could create a real landscape in which their train could navigate.
Though they were quite realistic in their time, they only improved their aesthetic appearance through the seventies, eighties, and nineties. One thing to note though is that the O scale is nowhere near as popular as the H0 or N scale which are a bit smaller and more convenient. The one advantage that the O scale can claim is a more detailed exterior. Smaller models simply could not do that, though they can be fairly close to real-world trains.
The O model railroad is a choice, and it is one that you will have to make as the modeler. Make sure that you weigh your options and of course determine whether or not you really have the room for an O scale train in your home or building. It can be more difficult to build scenery for a larger train if you do not have an adequately sized house, and that may further you need for smaller trains. If you have the room however, or simply wish to enjoy a basic train without the scenery, the O model railroad might be your best bet.
Just remember to assess your needs and make sure you are doing the right thing. Choosing the right model train and accessories is never easy, and the true choice will come from within. So long as you remember that you will do great, and you might even find that the O model railroad is for you, especially if you're interested in using a piece of model train history that simply never gets old.