The earliest known forms of writing represented words with pictures. Cuneiform started by the Sumerians and hieroglyphics used by the Egyptians were two of the original ways of communicating in written form. Egyptian pictographs had a cursive form called hieratic which was faster to write, was a freer, looser interpretation of the pictographs and featured ligatures (strokes connecting individual letters). The challenge of pictographic communication is the large number of symbols which must be memorized. Alphabets, on the other hand, represent the sounds of speech; so far fewer symbols need to be learned.
In 1999, a discovery of graffiti inscribed on a rock at Wadi el-Hol, Egypt, pushed back the origins of the development of an alphabet to between 1900 and 1800 BC. This early Semitic scrawl points to ties between Egyptian hieratic script and the earliest known alphabet. The first widely known alphabet was developed by the Phoenicians (from the Greek-coined phoiniki meaning "purple people" for the dye they sold around the Mediterranean) in about 1200BC. The alphabet represented consonants and was primarily used by merchants to record commercial transactions.
The accompanying chart shows the Phoenician alphabet around 1400 BC. The Phoenician alphabet is acrophonic meaning each letter represents the initial sound of the name of the letter. For example, the last letter in the Phoenician is called taw or tah (meaning mark) and led to our current letter T with the same sound.
The Greeks adapted that alphabet in the eighth century BC by adding vowels. The Etruscans borrowed the Greek alphabet which was later adopted by the Romans. These early scripts were most frequently written by pressing or scratching a stylus into a soft clay tablet which was then allowed to harden. By the first century BC, the Romans had developed several scripts. There was a cursive hand which could be quickly scratched into a wax tablet or written with a reed pen on paper made of papyrus. There was also a script called the Imperial Capital which was carved in stone and survives on monuments and buildings from the time. This script was also written using a brush on paper. All subsequent Western scripts have evolved from the Roman letters, in fact the Imperial Capital script serves as the basis for our modern capital letters.
Another important contribution of the Romans came in the fourth century AD when someone came up with the idea of cutting the scrolls, that had been in use until then, into oblong strips and then sewing the strips together down one side to form the first books. The advantage of a book is the ability to easily access information without unrolling an entire scroll.
Early cuneiform letters are combinations of straight lines. Later, circles and arcs were included, as the means to draw them became available. The Etruscan alphabet had 20 letters. The earliest Roman (Latin) alphabet had 21 letters. By the end of the Roman era, the letter Y and Z from the Greek letters Upsilon and Zeta had been added for a total of 23 letters. Then in medieval times, the letters J, U, and W were added to bring the total to the 26 letters of the modern alphabet.
Interestingly, the letter J started as a swash character for the last i at the end of Roman numerals after a series of "i" characters (for example, xviij meaning 23). It wasn't until 1524 that the letter J was given a distinctive usage in a treatise written by Gian Giorgio Trissino (1478-1550). The first English-language book to use the letter J in its new role was published in 1634.
The letter U is one of several letters derived from the Phoenician letter waw. The Romans used the V and Y from waw. Then during the late Middle Ages, two forms of "v" developed. The pointed form "v" was written at the beginning of a word, while a rounded form "u" was used in the middle or end, regardless of sound. So the words valor and excuse appeared as in modern printing, but the words "have" and "upon" were printed haue and vpon. The first distinction between the letters "u" and "v" is recorded in a Gothic alphabet from 1386, where "v" preceded "u". By the mid-16th century, the "v" form was used to represent the consonant and "u" the vowel sound. The capital letter for "U" was not accepted until many years later.
The earliest use of the double letter "uu" was in the 7th and 8th centuries AD by English and Germanic writers. The modern name comes from the digraph "uu". W is the only English letter whose name is not pronounced with any of the sounds that the letter typically makes. It gained popularity during the 11th century and was well established by the 13th century for central-western European writers. However, it wasn't considered a part of the Latin alphabet proper even as late as the 16th century.
The alphabet we use today has taken many centuries to develop to its modern form. There have been many twists, reversals in meaning, and changes to the sounds represented by particular symbols. Many languages have played a role in contributing both sounds and symbols. And this should not seem out of place, as language itself is a constantly evolving entity, responding to the varied changes in environment and contact with new peoples, cultures, and languages.