http://www.oecd.org/dataoecd/17/53/41558958.pdf tells me that non-commercial (government or government-subsidized) R&D represents ~1% of GDP in 2006 for the US. I believe equivalent figures for the 1800s would be closer to 0% R&D inasmuch as there were no Departments of Energy, Health & Human Services, etc., but I'm willing to be proven wrong. Maybe the Gilded Age governments in the US actually spent 2% of GDP on R&D.