Barack Obama won a U.S. Senate seat from which state after speaking at the 2004 Democratic National Convention?

Barack Obama won a U.S. Senate seat from Illinois after delivering a keynote address at the 2004 Democratic National Convention. This speech significantly raised his national profile and brought attention to his political career, ultimately leading to his successful campaign for the Senate seat. Obama's ability to connect with a diverse audience during that speech showcased his oratory skills and progressive vision, which resonated with voters in Illinois.

The other states mentioned do not relate to Obama's Senate run. New York, New Jersey, and Ohio had their own Senate representation and elections, but none of these states were involved in Obama's path to the Senate. His victory in Illinois, where he served from 2005 to 2008, laid the groundwork for his future presidential campaign.