On July 30, 1866, black Republicans attempted to reconvene the Louisiana constitutional convention in an effort to secure voting rights. Held at the Mechanics' Institute, a large crowd of black spectators was present as well. The gathering was attacked by an angry white mob that included police and firemen.  According to the Tribune, "black men were assassinated by scores. They fell inside of the hall, outside of the building, in the neighboring streets, and even in distant parts of the city, where they were tracked like dogs."  Tribune editor Jean-Charles Houzeau witnessed the bloodbath and heard the assassins shout "To the Tribune!" He claimed the newspaper was saved by a detail of black soldiers. 
Louisiana was clearly incapable of reconstructing itself. The horror in New Orleans became an enormous national news story, tipping the fall congressional elections heavily in favor of Radical Republicans and significantly damaging President Johnson's policies of accommodation with ex-Confederates. The new Republican controlled Congress wasted no time in passing four aggressive Reconstruction Acts. Louisiana was to be treated like a conquered enemy, and for the state to be readmitted to the Union, it had to create a new state constitution with strong equal rights provisions.
In late 1867 and early 1868, the constitutional convention in Louisiana drafted and enacted the most sweeping and radical state constitution in the American South. This historic body was composed of an almost equal number of black and white delegates. Many of the Tribune platforms were realized in the new charter, including black men’s right vote. The new state legislature included many black representatives. They would go on to enact the most far reaching and progressive legislation in the American South, including, unique to the entire south, an integrated public school system that was in place in New Orleans from 1872 to 1877. 
Harper's Weekly devoted an entire issue to the massacre, including the grim full page graphic illustration "Timely Warning to Union Men. The New Orleans Convention or Massacre," which appeared on September 8, 1866.