That I agree with. I only took issue with the idea that no one knew what Dr. Who was in the states.
The first episode of
Dr. Who was broadcast 23 November 1963 in the UK.
I read about
Dr. Who in the USA in a magazine about science fiction and fantasy movies and tv shows - probably Famous Monsters of Filmland or Castle of Frankenstein. I read one article mentioing
Dr. Who. The article had one or more stills from "The Web Planet" (13 February to 20 March 1965) and so would have been published in 1965 or later. And I got the impression that
Dr. Who mostly looked like "The Web Planet".
There was a movie based on
Dr. Who,
Dr. Who and the Daleks (1965), and I remember the American comic book, released in December 1966, based on the movie. I think that I bought.and read it in the waiting room at Reading Terminal, Philadelphia. So I should have acquired a more accurate idea of Dr. Who from that comic book.
https://tardis.fandom.com/wiki/Dr._Who_and_the_Daleks_(comic_story)
When I saw
Carrry On Screaming (1966) during the period of 1968-1972, it had a joke where Dr. Watt introduced himself and someone said; "Who?" and Watt said "No, Watt. Who's my cousin." So I deduced from that joke that
Dr. Who was popular in Britain.
In the very early 1970s, some recent serials of
Dr. Who were shown on American television. I remember seeing the last scene in the last episode of "Dr. Who and the Silurians", which aired 14 March 1970 in the UK, when shown in the USA, probably only a year or two latter, and possibly some other episodes as well.
I remember that was several years before The first batch of 4th Doctor Tom Baker episodes (1974-75 in Britain) were shown in the USA.
So people in the USA interested in science fiction movies and tv shows could be aware of
Dr. Who long before it became popular in the USA during the middle and late 1970s, even in the 1960s.
I can't think of any obvious examples of any US science fiction movies or shows influenced by
Dr. Who.
One possible example would be "Spectre of the Gun", first broadcast on 25 October, 1968. The idea might have been suggested by the
Dr. Who serial "The Gunfighters" broadcast from 30 April to 21 May 1966. Lee Cronin first submitted his story outline for "Spectre of the Gun" on 6 March 1968, so it is theoretically possible that he might have heard about "The Gunfighters" and been inspired to do an "gunfight at the OK Corral" story. But there may be some evidence somewhere about what his inspiration was.
https://memory-alpha.fandom.com/wiki/Spectre_of_the_Gun_(episode)#Production
I have argued that some aspects of the serial "The Keeper of Traken" (31 Janaury to 21 February 1981) show influences of other SF works. Something reminds me of "The Terrible Clockman",
Shirley Temple's Storybook (January 29, 1961), and some plot elements seem derived from "Flight of the War Witch"
Buck Rogers in the 25th Century (March 27, 1980), while a name seems influenced by the
Silmarillion (1977).