Indiana National Bank was once a premier financial institution and the largest state-chartered bank holding company headquartered in Indianapolis, Indiana, tracing its corporate lineage back to the founding of the Second State Bank of Indiana. Over decades of operations, it expanded aggressively through county acquisitions and consolidated its branding under the INB Financial Corporation banner. During the nationwide wave of interstate banking deregulation and financial consolidation in the early 1990s, the institution became an acquisition target. It was acquired by Michigan-based NBD Bancorp in a massive multi-million-dollar transaction, which subsequently merged all separate INB banking units into a single regional network, effectively ending its independent existence.