What's wrong with the 1800's? Is Darwin's Origin of the Species invalid because it is old?
Are you suggesting that before the 1900's there was no government cover-up? If so......:
Seleucus of Seleucia: discovery of tides being caused by the moon in the 10th century
Nicole Oresme: discovery of the curvature of light through atmospheric refraction in the 14th century
1543 – Nicolaus Copernicus: heliocentric model
1570s – Tycho Brahe: detailed astronomical observations
1600 – William Gilbert: Earth's magnetic field
1609 – Johannes Kepler: first two laws of planetary motion
1610 – Galileo Galilei: Sidereus Nuncius: telescopic observations
1619 - Johannes Kepler: third law of planetary motion
1687 – Sir Isaac Newton: classical mathematical description of the fundamental force of universal gravitation and the three physical laws of motion
1865 – Rudolf Clausius: Definition of Entropy
1877 – Ludwig Boltzmann: Statistical definition of entropy