HO trains became popular with model train collectors in the 1950's as discontent grew with the OO scale trains. A viable alternative was needed to meet the demands of the ballooning model train collectors. The HO model train was able to fill this need with the advent of mass production.The HO model train was perfected in its infancy by a company called Lionel. Lionel is now a household name for model trains primarily because of their innovation and attention to detail. By creating a model train that closely mimicked the real thing they were able to capture the attention and following of model train collectors worldwide.
The HO model trains were rather large and took up a lot of space so they invented the N and the Z scale model trains. At roughly half the size of the HO model train the N scale was a welcome alternative for those that wanted to collect trains and still be able to find a place in their homes to set up the train sets. The Z scale model trains were one third the size of their big brother the HO trains. Deep down the consensus was that if you had the HO model train you had the best.
Not to be outdone the major model train manufacturers created several larger versions of the HO Model Train. The HO's larger brothers were the O, S and G scale model trains. The S scale model train is 1/3 larger than the HO Model Trains and brought another level of uniqueness and excitement to the model railroading community. The O scale is twice the size of the HO Model Trains and the G scale is just a behemoth in terms of size. The G scale trains are also designed to run outside and can also be run indoors if you have enough space to run these beasts of the modern railroading community.
The HO model train is still considered to be the most sought after model trains. Especially the vintage models that represent a time of innocence and sense of nostalgia. If you are really serious about your model trains then find yourself a well preserved antique train set and watch the envious eyes of your fellow hobbyists.
As a footnote you may also want to consider the Hornby Trains as a great addition to any model train set.
