Final answer:
The state that includes the Allegheny, Susquehanna, and Delaware Rivers, and shares the Ohio River with New Jersey, is Pennsylvania. Specifically, the Allegheny and Monongahela Rivers meet at Pittsburgh, which is historically significant for its steel industry.
Step-by-step explanation:
The state that contains the Allegheny River, Susquehanna River, Delaware River, and shares the Ohio River with New Jersey is Pennsylvania.
The Allegheny and the Monongahela Rivers converge in Pittsburgh, creating a significant confluence that played a historic role in the development of the steel industry.
Research conducted on Pennsylvania streams, such as in the work by Argent and Carline (2004), examines patterns within the state's three major drainages: Delaware, Susquehanna, and Ohio.
This richness in aquatic biodiversity and significant historical events, like George Washington's attempts to negotiate with the French at the convergence of these rivers, highlights Pennsylvania's unique geographic and historical position.