It's hard to measure precisely how popular it was historically but he campaigned for Mayor of NYC as a Georgist and finished 2nd ahead of Teddy Roosevelt who fi

It's hard to measure precisely how popular it was historically but he campaigned for Mayor of NYC as a Georgist and finished 2nd ahead of Teddy Roosevelt who finished 3rd. So Henry George at least was well liked. The book itself was the best selling economics book of the 19th century. It inspired art demonstrations and some governments throughout the world even adopted LVT for a while. So yes, it was pretty popular.