I would like to see this answered as a specification: Was this the case at the time? I know there were efforts on the national level for at least material intervention, but how concerned were the general populaces?

I think it was better understood by Americans at the time than it is today. American's had been deeply involved in missionary work in China for many years. Also the US Navy Yangtze River Patrol was based in and patrolled Chinese waters from 1854-1949. Starting in 1927 there was a US Marine Regiment stationed in Shanghai. As a result there was much knowledge of the plight of China, especially after the Paney Incident in 1937 when the Japanese attacked the US gun boat USS Paney . There were many organizations involved in fundraising and education efforts to bring aid to China. For example United China Relief was founded in 1941 to reduce overhead and duplication of effort by a number of preexisting relief organizations including: American Bureau for Medical Aid to China, the Associated Boards for Christian Colleges in China, the China Emergency Relief Committee, the Church Committee for China Relief, and the China Aid Council. More info on United China Relief can be found in the records of the NYPL here http://archives.nypl.org/mss/3078

u/mustaphamondo answered a similar question and talked about how the historiography of the war developed from a US context.