What was similar about warfare in the early 1800s and early 1900s ww1

The answer is: All the nations involved formed a network of alliances in order to secure their victories.

Before that time period, many nations often rely on their own poer in order to show their 'might' to the rest of the nations. In the early 1800s, wars based on alliances become much more common since they can cut down the overall millitary budget, make it easier to obtain strategic location in the war, and make the chain of supply become easier during the war.