They maintained their own identities instead of "melting together" like described in the melting pot.
Civilizations connected through trade first via trading tools with other nearby communities then it evolved into trading more goods such as foods crops and weapons. Then with boats this allowed technology and customs to travel for example Egyptian sculptures influencing Greek art work and the silk road. This helped humanity since a example of isolation was japan until the Miji Restoration. Humanity needs trade in order to communicate and get things they cannot make in their region of the world.
The Bessemer Process was an extremely important invention because it helped made stronger rails for constructing the railroads and helped to make stronger metal machines and innovative architectural structures like skyscrapers. The United States Industrial Revolution moved from the Age of Iron to the Age of Steel.