Information sharing among U.S. law enforcement agencies has evolved substantially since 9/11, including the sharing of crucial information among disciplines and jurisdictions through relationships that were nonexistent prior to 9/11. But with these new relationships come emerging challenges in overcoming “silo-thinking,” as well as legal, procedural, and fiscal constraints. State and local law enforcement agencies are at the forefront of this evolution, yet they may not fully recognize how crucial their role is. This article examines milestones in the U.S. information sharing architecture, three key initiatives born of post-9/11 reform, vital stakeholders involved, the challenges that remain, and a vision for the future.