Guzman, 61, is charged with 10 criminal counts, including drug trafficking and engaging in a criminal enterprise as leader of Mexico's Sinaloa Cartel. Cogan says it made him "very proud to be an American".
He could face life behind bars in a maximum security US prison.
The verdict came on the sixth day of the jury's deliberations.
A grand jury in New York City found Mexican drug cartel kingpin Joaquin "El Chapo" Guzman guilty on all counts; setting the stage for a high-stakes sentencing hearing that could send the global criminal to prison for the rest of his life. His sentencing is set to be announced on June 25th.
The trial testimony lasted almost three months and the jurors have been tasked with deciding on 10 separate counts. Many described Guzman's willingness to use violence against enemies of a cartel that prosecutors say smuggled at least 200 tons (181 metric tons) of cocaine into the USA over two decades.
Guzman escaped twice from maximum-security Mexican prisons before his final capture in January 2016.
They had returned Tuesday to grapple with the complicated case at a federal courthouse in Brooklyn. Fourteen of those witnesses - mostly admitted drug traffickers and cartel associates - were cooperating with prosecutors in hopes of reducing their own prison sentences.
In a series of notes last week, the jury sought answers to legal questions and asked to review days of testimony from several of the cooperators.
More than 50 witnesses testified during the 11-week trial, including 14 former associates of Guzman who had agreed to cooperate with USA prosecutors. Many described Guzman's willingness to use violence against enemies of a cartel that prosecutors say smuggled at least 200 tons (181 metric tons) of cocaine into the US over two decades.