Thousands of students, activists and scientists gathered in downtown Los Angeles this weekend for the March for Science event.
March for Science rallies were held all over the country with more than 500 events held in cities like Boston, San Francisco, New York and Chicago.
The marches were held to support science and evidence based research.
The main march was held in Washington DC with TV host and scientist Bill Nye as the featured speaker.
"Today we have a great many lawmakers -- not just here but around the world -- deliberately ignoring and actively suppressing science."
President Trump's administration has said they are committed to keeping our air and water clean, preserving the environment and protecting endangered species.
However, Trump has proposed to cut $6 million from the National Institutes of Health and has dismissed climate change as a "Chinese hoax."
In Los Angeles several speakers were at the march that led to City Hall to address the crowd.
Oscar-nominated "Hidden Figures" screenwriter Allison Schroeder, celebrity seismologist Lucy Jones and billionaire climate change activist Tom Steyer were among those who spoke.