The ACT-America Campaign Catalog provides information about the airborne campaigns of the Atmospheric Carbon and Transport (ACT-America) project. ACT-America advanced atmospheric greenhouse gas inversions to a high level of accuracy and precision through new methods and models that improved knowledge of atmospheric transport, prior flux models, and space-based observations. The catalog compiles flight details for the five campaigns conducted during Summer 2016, Winter 2017, Fall 2017, Spring 2018, and Summer 2019 (2016-05-27 to 2019-07-26) across three regions of the eastern and central United States. Data include flight dates, regions, objectives, weather conditions, instrument status, aircraft flight paths, detailed weather reports, and measurement summary figures. A total of 121 research flights were conducted within the five six-week seasonal campaigns by each of the two instrumented aircraft platforms, the NASA Langley Beechcraft B-200 King Air and the NASA Wallops Flight Facility's C-130 Hercules. During 1,140 flight hours remote and in situ sensors onboard the two research aircraft measured greenhouse gas mole fractions, trace gases, and thermodynamic variables across a variety of continental surfaces and atmospheric conditions to study the transport and fluxes of atmospheric carbon dioxide and methane. As noted in the Flight_patterns_staus field, there were flights when both aircraft flew directly under Orbiting Carbon Observatory-2 (OCO-2) overpasses to evaluate the ability of OCO-2 to observe high-resolution atmospheric CO2 variations. The C-130 aircraft was also equipped with active remote sensing instruments for planetary boundary layer height detection and column greenhouse gas measurements. The data are provided in comma separated values (CSV), compressed Keyhole Markup Language (KMZ) formats along with figures as JPEG and Portable Network Graphics images.