Until the previous discussion on valuation I had always assumed that it
started after 1913. However, upon hearing Tony's and others' reference to
earlier instances of valuation activity, it piqued my curiosity so I checked
into some of my references. Valuation was part of the effort to establish
what a "fair rate of return" for railroads' investment was. According to
Locklin (Economics of Transportation 1972) in 1898 the Supreme Court stated
that rate reasonableness should be based on property value. In 1903 the ICC
recommended that a valuation of the railroads be made. Presumably neither of
these had the force of law and Locklin states that initially the RRs were
opposed. However, in 1910 RRs some railroad requests for rate increases were
turned down because of a lack of proof from the RRs regarding the
reasonableness of the propsed increase and this was partly due to lack of
valuation data. So the RRs became motivated to pursue valuation and
according to Locklin their opposition to it had ceased by 1913. I recall
reading somewhere else that the result of the ensuing valuations was the
finding that RR assets were worth more than had generally been presumed, so
thay ended up having an even stronger case for rate increases.

Chris