Understanding and controlling the dynamic self-assembly mechanisms of carbon nanotube (CNT) forests is necessary to advance their technological im-pact. Here, in-situ environmental scanning electron microscope (ESEM) chemical vapor deposition (CVD) synthesis observes in real time the real-time nucleation, assembly, delamination, and self-termination of dense (> 109 CNT/cm2), tall (> 100 μm) CNT forests. Forest synthesis is continuously ob-served from nucleation to self-termination. Assembly forces generated near the substrate detach CNTs from the substrate, which simulation suggests requires between 3 and 12 nN of tensile force. Delamination initiates at both the CNT-catalyst and the catalyst-substrate interfaces, indicating multiple delamination mechanisms. Digital image correlation applied to SEM image sequences measures time-invariant strain within growing forests, indicating that forests grow as rigid bodies after liftoff. The Meta CoTracker algorithm measured CNT growth rates reduce from 50 nm/s to full termination over 150 s. The kinematic behaviors we observe are foundational to understanding the process-structure-property relationships of CNT forests.