It's been going on a lot longer than you think.
YEAR - PATENT NUMBER - PATENT NAME
1891 – US462795A – method of producing rain-fall
1914 – US1103490A – rain maker (balloon images)
1917 – US1225521A – protection from poisonous gas in warfare
1920 – US1338343A – process and apparatus for the production of intense artificial clouds, fogs, or mists
1924 – US1512783A – composition for dispelling fogs
1927 – US1619183A – process of producing smoke clouds from moving aircraft
1928 – US1665267A – process of producting artificial fogs
1932 – US1892132A – atomizing attachment for airplane engine exhausts
1933 – US1928963A – electrical system and method (for spraying chemtrails)
1934 – US1957075A – airplane spray equipment
1936 – US2045865A – skywriting apparatus
1936 – US2052626A – method of dispelling fog (mit)
1937 – US2068987A – process of dissipating fog
1939 – US2160900A – method for vapor clearing
1941 – US2232728A – method and composition for dispelling vapors
1941 – US2257360A – desensitized pentaerythritol tetranitrate explosive
1946 – US2395827A – airplane spray unit (us. dept. of agriculture)
1946 – US2409201A – smoke-producing mixture
1949 – US2476171A – smoke screen generator
1949 – US2480967A – aerial discharge device
1950 – US2527230A – method of crystal formation and precipitation
1951 – US2550324A – process for controlling weather
1951 – US2570867A – method of crystal formation and precipitation (general electric)
1952 – US2582678A – material disseminating apparatus for airplanes
1952 – US2591988A – production of tio2 pigments (dupont)
1952 – US2614083A – metal chloride screening smoke mixture
1953 – US2633455A – smoke generator
1954 – US2688069A – steam generator
1955 – US2721495A – method and apparatus for detecting minute crystal forming particles suspended in a gaseous atmosphere (general electric)
1956 – US2730402A – controllable dispersal device
1957 – US2801322A – decomposition chamber for monopropellant fuel
1958 – US2835530A – process for the condensation of atmospheric humidity and dissolution of fog
1959 – US2881335A – generation of electrical fields (haarp – for re-charging clouds!)
1959 – US2903188A – control of tropical cyclone formation
1959 – US2908442A – method for dispersing natural atmospheric fogs and clouds
1960 – US2962450A – fog dispelling composition (see references)
1960 – US2963975A – cloud seeding carbon dioxide bullet
1961 – US2986360A – aerial insecticide dusting device
1962 – US3044911A – propellant system
1962 – US3056556A – method of artificially influencing the weather
1964 – US3120459A – composite incendiary powder containing metal coated oxidizing salts
1964 – US3126155A – silver iodide cloud seeding generator (main commercial ingredient)
1964 – US3127107A – generation of ice-nucleating crystals
1964 – US3131131A – electrostatic mixing in microbial conversions
1965 – US3174150A – self-focusing antenna system (haarp)
1966 – US3257801A – pyrotechnic composition comprising solid oxidizer, boron and aluminum additive and binder
1966 – US3234357A – electrically heated smoke producing device
1966 – US3274035A – metallic composition for production of hydroscopic smoke
1967 – US3300721A – means for communication through a layer of ionized gases (haarp)
1967 – US3313487A – cloud seeding apparatus
1967 – US3338476A – heating device for use with aerosol containers
1968 – US3410489A – automatically adjustable airfoil spray system with pump
1969 – US3429507A – rainmaker
1969 – US3430533A – aircraft dispensor pod having self-sealing ejection tubes
1969 – US3432208A – fluidized particle dispenser (us air force)
1969 – US3437502A – titanium dioxide pigment coated with silica and aluminum (dupont)
1969 – US3441214A – method and apparatus for seeding clouds
2001 -US20030085296A1 - Hurricane and tornado control device
Of Weather Control Or Modification Patents
https://patents.justia.com/patents-by-us-classification/239/2.1