On April 22, 1970, millions of people took to the streets to protest the negative impacts of 150 years of industrial development. Earth Day is now an annual global event, with more than 1 billion people in 192 countries taking part in what is the largest civic-focused day of action in the world. It is a day of political action and civic participation. People march, sign petitions, meet with their elected officials, plant trees, and clean up their towns and roads. Corporations and governments use it to make pledges and announce sustainability measures. The theme for 2019’s Earth Day is about protecting threatened and endangered species.