It may be quite interesting to compare how two main Soviet cosmodromes were being built and made operational in 1950-60s.
History of Tyuratam (Baikonur cosmodrome):12.01.1955 Arrival at the Tyuratam railway station of the first unit of military builders to prepare the deployment sites, construction, and installation infrastructure. The construction of the settlement begins.
12.02.1955 Order of the Council of Ministers of the USSR on creation of a test site for intercontinental ballistic missiles.
20.07.1955 Construction of the first launch pad begins.
15.05.1957 The first R-7 rocket is launched from the cosmodrome.
12.01.1955 - 15.05.1957 => less than 1.5 years.History of Angara (Plesetsk cosmodrome):11.01.1957 Order of the USSR government on creation of the military facility Angara.
15.03.1957 Construction of the facility began 180 kilometers south of Arkhangelsk, in close proximity to the railway station of Plesetskaya of the Northern Railway.
Between 1957 and 1963, nine launch complexes were built at the Angara facility, including 15 launch pads for four types of missiles: R-7/R-7A, R-16, R-16U, and R-9A.
22.10.1963 The first launch. R-16U ballistic missile was launched from a silo.
15.03.1957 - 22.10.1963 => more than 6.5 years.With the introduction of the 2nd (Plesetsk) cosmodrome the Soviet government seemed to be very tolerant.

They kept waiting till the very last launch pad was built and only after that started launches.