MacRobbie said that, "Roger played a huge part in the development of the Plant Biophysics group, and his legacy and legend lasted for years.

Spanswick joined the plant physiology group at Cornell University that included André Jagendorf, Peter J. Davies, and others.

[1][2] He was an active member of the Friday Lunch Club, which included A. Carl Leopold, Randy Wayne, and others.

He also showed that the gradients of pH and membrane potential generated by the primary proton pump in the plasmalemma could be used to drive secondary active transport of other solutes, sugars, amino acids and other ions.

Thus his original idea led to a very large volume of experimental work, in which he also had a major input, and the consequence was a revolution in the field.

He is interred in Pleasant Grove Cemetery in Ithaca, New York, where his gravestone is inscribed with the phrase "only connect" from the 1910 book Howards End by E. M. Forster.