The microscope was created to see tiny things more clearly for scientists.
Zacharias Janssen created the microscope so scientists could see tiny things more clearly. Scientists "jumped" at the opportunity to use the microscope Janssen created.
Robert Hooke was working with Leeuwenhoek. Leeuwenhoek was sending him his discovery of bacteria. Hooke then decided to look at a cork under the microscope. He saw tiny little rectangles. He then named it cells because they looked like monk cells.
Anton van Leeuwenhoek made his own microscope after Janssen and looked at different things using it. He then looked at the bacteria on his teeth and discovered bacteria.
Schleiden discovered that all plants have cells. He looked at plenty of plants and realized this.
Schwann looked at animal cells under the microscope. Just like Schleiden, Schwann discovered that all animals have cells.
Schleiden didn't think that cells came from preexisting cells like Schwann did. Schleiden thought that cells just randomly popped up. Virchow came in and told them that cells indeed came from preexisting cells, proving Schleiden wrong.
The Cell Theory was officially created. The first part was "All living things are composed of cells". The second part was "Cells are the basic units of structure and function in living things." The third, and last, part of the cell theory was "All cells are produced from other cells." Even though Schwann, Schleiden, and Virchow wrote the Cell Theory, all of these scientists played an important part to creating it.