3,500 – 3,000 B.C. – Florescent and Proto-literate Periods
Florescent in this case refers to a period of rapid growth in the civilization. Sumer’s development accelerated with many new villages becoming prominent. One of the most notable was Erech, which has been well excavated. Crafts were well-developed – pottery, carpentry, and metallurgy. The presence of wood and metals from great distances indicates advanced trade.
Writing began with the form of pictographs but advanced along with numerical notation. The plow was improved, wheeled carts were constructed, and sailboats put into use. Bronze weapons and tools were seen after 3000 B.C.