Many people who were first influenced by Henry George's ideas became impatient with the "organicness" of them, and moved to promoting socialism because they thought it would achieve their objectives more quickly. But George was convinced that it had to grow organically.

George Bernard Shaw was perhaps the most famous of them.

Henry George had public debates with several socialists (Serge Shevitch was one - 1887; Henry Hyndman another). They're great reading.