How Did Physicists Determine the Speed of Light?

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This isn't on why the speed of light is the cosmic speed limit. I want to know how did physicist determine it? What experiment did they perform? What calculations did they make? They obviously didn't go into outer space and shined a light then see how long it took. Did they use a telescope? Help!
 
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I did some google:
http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html

One can also measure the speed of light by measuring masses of particles (E = mc^2) etc.
 
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