Short answers, pulled from the story.
NAFTA came into effect on the 1st of January, 1994. It was signed by Canada, Mexico, and the United States, creating a trilateral trade bloc that ranked among the largest in the world by gross domestic product.
President Bill Clinton added the North American Agreement on Labor Cooperation (NAALC) and the North American Agreement on Environmental Cooperation (NAAEC) before sending NAFTA to the Senate, to protect workers and the environment and to address concerns from House members. The U.S. House passed the implementing legislation on the 17th of November, 1993, by a vote of 234 to 200.
The Zapatista Army of National Liberation (EZLN) launched an armed rebellion in Chiapas, Mexico, on the 1st of January, 1994, the same day NAFTA took effect. An estimated 200 fighters seized five municipalities, declaring NAFTA a death sentence to indigenous communities. The uprising was triggered in part by Mexico's repeal of Article 27 of its constitution, which had protected indigenous communal land from privatization, a change made to accommodate NAFTA's investment rules.
From 1991 to 2007, 4.9 million Mexican family farmers were displaced as subsidized U.S. corn imports undercut domestic prices. Political scholar Courtney Jung noted that for the 3 million Mexican farmers on small, rain-dependent fields without irrigation, NAFTA was a disaster. Real average wages for minimum wage workers in Mexico fell by 14 percent over NAFTA's first six years according to Global Trade Watch.
Chapter 11 allowed corporations and individuals to sue NAFTA member governments directly for compensation when government actions violated international law. Notable cases included Methanex Corporation's US$970 million suit against the United States and Metalclad Corporation's successful US$15.6 million award from Mexico.
The United States-Mexico-Canada Agreement (USMCA) replaced NAFTA. All three countries ratified it by March 2020, and it took effect on the 1st of July, 2020. Renegotiation began after Donald Trump's 2016 election; a preliminary deal was reached on the 30th of September, 2018.