  The RHIC Cold QCD program has produced a remarkable breadth of physics
results and experimental techniques in the exploration of the fundamental
structure of strongly interacting matter over the years. In this document, we
present highlights of longitudinal and transverse spin physics to date and the
25 years of innovation in accelerator science from the RHIC Spin program. These
measurements and techniques will be essential to fully realize the scientific
missions of the Electron-Ion Collider (EIC) by providing a comprehensive set of
measurements in hadronic collisions and laying the foundation for the design of
the future EIC.
