piker wrote: New York railroads were 6' 0", New England was almost completely 4' 10" and the Portland and Ogdenburg was 5' 6". How was the standard gauge agreed upon and when and how long did it take to implement? Why the smaller gauge?
Thats probably just a broad generalization for the purposes of the map..
Standard Gauge began all over NY state in the 1840's..through the 1850's huge amounts of Standard gauge track was built in the North East,
and by the Civil War standard gauge was MUCH more common than 6-foot gauge across NY state..(the New York Central was well established by the 1860's, in standard gauge) Many of the ancestors of the Anthracite roads across PA were also quite well developed, and all standard gauge by this time..
So I think the book is pretty innacurate if it suggests that all of NY state was 6-foot gauge in the 1860's..this is far from true.
President Lincoln chose standard gauge for the Transcontinental railroad because it was the most established gauge in the North East in the 1860's,
and also because it would be fairly easy for the Southern railroads, at 5-foot gauge, to regauge by just moving one rail..
the Erie and DL&W also had to eventually move in a rail on their 6-foot gauge lines..
it was easier to re-gauge narrower than wider..(wider might require new ties, narrower wouldnt) and the New York Central, PRR, B&O and other major Northern railroads were already standard gauge by the Civil war..so choosing that as the standard for the whole nation made the most sense.
And once the Transcontinental railroad was built to standard gauge (completed in 1869), it was inevitable that standard gauge would become "the standard gauge" for the whole nation..