It has long been challenging for researchers to track the crustal evolution and mode(s) of crustal modification in ancient convergent margins, limiting evaluation of the tectonic styles and processes that modify continental crust during orogenesis. Hence it is critical to constrain the timing, extent, and duration of mountain building events and evolution of Earth’s crust through Earth history. However tracking the rise and fall of ancient mountain building events is challenged by many factors including limited preservation and exposure, the removal of once high peaks by erosion, overprinting of fabrics and mineral assemblages by subsequent tectonic processes, and attributing geochronologic dates from metamorphic rocks to specific reactions, deformation(s), and pressure-temperature conditions. Research presented herein develops methods that link absolute age constraints with geochemical data to track the rise and fall of complex ancient orogenic belts. I apply this approach to rocks of the New England Appalachians and Southwest USA, which are widely recognized as type examples of multi-stage accretionary and collisional orogenesis. Results from New England provide new insights into terrane accretion, growth of an orogenic plateau, and gneiss dome development with implications for understanding deep crustal processes beneath the modern Himalayan-Tibet-Karakoram orogen. Quantitative paleo-crustal thickness and geobarometric estimates from the Southwest USA suggest a transition from 1.75–1.69 Ga short-lived crustal thickening associated with terrane accretion to 1.69–1.60 Ga largely extensional accretionary orogenesis, and regional, long-lived crustal thickening at 1.47–1.37 Ga involving extensive magmatic underplating. This documents complex mountain building styles in contrast with models proposing orogenic quiescence in this time period. Finally, I pair microanalytical work with geochemical and isotopic databases to resolve the nature and evolution of Paleoproterozoic crustal growth and accretion in the Southwest USA. The 1.8-1.7 Ga Yavapai Province is widely regarded as a classic example of juvenile arc crust, however the occurrence of 1.8-2.5 Ga inherited zircon and Nd and Hf model ages have led to questions regarding the extent and nature of pre-1.8 Ga crustal material and the genesis of the Yavapai Province. I present evidence for a geochemically distinct, spatially restricted crustal block underlain by pre-1.8 Ga crust material (referred to here as the Gunnison block) in central to western Colorado within the Yavapai Province. The Gunnison block accreted to other components of the Yavapai Province outboard of Laurentia at 1.75-1.74 Ga. The composite Yavapai Province was accreted to the margin of Laurentia during the 1.72-1.69 Ga Yavapai orogeny. Identification of distinct crustal terranes within the Yavapai Province supports models involving multiple arcs and back-arcs that were progressively assembled prior to their accretion to Laurentia, perhaps akin to the present-day Banda Sea in Indonesia. I show that this approach can constrain the rise and fall of ancient mountain belts, crustal growth, and tectonic processes. Insights into the evolution of middle and lower crust provided by this study provide a basis for understanding processes such as partial melting, ductile flow, and magmatic underplating underneath modern plateaus and orogens.