United States History On This Date: March 26

1804 — Congress Organizes the Louisiana Territory

Following the Louisiana Purchase, Congress formally created the Territory of Orleans and the District of Louisiana. This administrative step laid the groundwork for American expansion, governance, and settlement across a vast region that would eventually form multiple states.

1812 — Earthquake Shakes New Madrid Region

A powerful aftershock of the New Madrid earthquakes struck the Mississippi Valley, part of one of the most intense seismic sequences in U.S. history. The quakes altered landscapes, redirected waterways, and deeply affected frontier communities.

1953 — Dr. Jonas Salk Announces Polio Vaccine Success

Medical researcher Jonas Salk reported successful trials of his inactivated polio vaccine. The breakthrough offered hope against a disease that had terrified American families for decades and marked a turning point in modern public health.

1979 — Egypt–Israel Peace Treaty Signed

At the White House, President Jimmy Carter hosted the signing of the Egypt–Israel Peace Treaty. The agreement, rooted in the Camp David Accords, reshaped Middle Eastern diplomacy and marked a major U.S. achievement in international mediation.

Egyptian President Anwar Sadat, U.S. President Jimmy Carter and Israeli Prime Minister Menachem Begin share a laugh at the signing of the Camp David Accords on September 17, 1978.