Dr Pepper was created in 1880 by Charles Alderton, it was first served in Waco Texas in 1885 and was available nationally by 1904, this actually means it was developed before Coca-cola. There are several stories as to where the name 'Dr Pepper' came from but despite the different versions it's pretty clear that it was named after Dr. Charles T. Pepper, a chemist that gave Alderton his first job.
The actual flavors and ingredients in Dr Pepper have always been a closely guarded secret, apparently each half of the recipe is stored in two separate bank vaults to ensure that no one can see the whole thing at once.
Since its original release the flavors in Dr Pepper have been guessed at, one idea was that it had prune juice in it, this has since been denied by the company but other than that everything else is a guess.
A survey in America claimed that Dr Pepper was in fact the 10th best selling soft drink. Its popularity worldwide is also obvious as it seems to be available almost anywhere.
Dr Pepper is also available in a diet version, which has been around since 1962, and as a caffeine free version since 1982. A few other extra versions they have are 'Dr Pepper Cherry Vanilla' and 'Dr Pepper Cherry' both of these are similar to regular Dr Pepper but taste of either the cherry or the vanilla is more prominent.
They also made 'Heritage Dr Pepper' this is made to the original recipe using real cane sugar instead of HFCS. A similar 'Dublin Dr Pepper' is also made in the same way but this is only produced in one factory where the owner refused to stop using real sugar when everywhere else started to use HFCS. Dublin Dr Pepper though is only available in Dublin Texas and only produced in limited amounts.
In the UK the Dr Pepper sold is similar to both the Heritage Dr Pepper and the Dublin Dr Pepper as it also uses cane sugar rather than HFCS. The UK also sells a zero version which has no added sugar but still retains the taste (apparently!) of the original unlike the diet version.
It's clear everywhere you look though that Dr Pepper is extremely popular with a lot of people claiming that its tastes so unique that it's one of those things you'll either love or hate. This 'love it or hate it' attitude around the drink shows with the 'love it' fans of the drink claiming it to be the best drink ever made. While people who 'hate it' claim that the taste reminds them of medicine.
It is available throughout America with the price of a 2l bottle ranging from around $1.50-$2. It is also available throughout the UK with the price of a 2l bottle being around £1.66 - you'll pay a fair bit more if you want an American version and I can't tell the difference.