It was shared between television and other systems. By 1950, television moved and that band was permanently dedicated to the opposition:
From 1945 to 1948 TV stations in the U.S. shared Channel 1 and other channels with fixed and mobile services. The FCC decided in 1948 that a primary (non-shared) allocation of the VHF radio spectrum was needed for television broadcasting. Except for selected VHF frequencies in Alaska and Hawaii (and some overseas territories) the FCC-administered VHF band is primarily allocated for television broadcasting to this day.
The FCC in May 1948 formally changed the rules on TV band allocations based on propagation knowledge gained during the era of shared-user allocations. The 44–50 MHz band used by Channel 1 was replaced by lower-power narrowband users.
Channel 1 was reassigned to fixed and mobile services (44–50 MHz) in order to end their former shared use of other VHF TV frequencies. Rather than renumber the TV channel table, it was decided to merely remove Channel 1 from the table.
The featured image comes from Channel One, a news service presented in many schools (including my own elementary school, a very long time ago).