--- old/make/data/tzdata/northamerica	2016-10-24 12:21:35.481653671 +0530
+++ new/make/data/tzdata/northamerica	2016-10-24 12:21:35.345653671 +0530
@@ -47,8 +47,32 @@
 # was the result of his proposals at the Convention of Railroad Trunk Lines
 # in New York City (1869-10).  His 1870 proposal was based on Washington, DC,
 # but in 1872-05 he moved the proposed origin to Greenwich.
-# His proposal was adopted by the railroads on 1883-11-18 at 12:00,
-# and the most of the country soon followed suit.
+
+# From Paul Eggert (2016-09-21):
+# Dowd's proposal left many details unresolved, such as where to draw
+# lines between time zones.  The key individual who made time zones
+# work in the US was William Frederick Allen - railway engineer,
+# managing editor of the Travelers' Guide, and secretary of the
+# General Time Convention, a railway standardization group.  Allen
+# spent months in dialogs with scientific and railway leaders,
+# developed a workable plan to institute time zones, and presented it
+# to the General Time Convention on 1883-04-11, saying that his plan
+# meant "local time would be practically abolished" - a plus for
+# railway scheduling.  By the next convention on 1883-10-11 nearly all
+# railroads had agreed and it took effect on 1883-11-18 at 12:00.
+# That Sunday was called the "day of two noons", as the eastern parts
+# of the new zones observed noon twice.  Allen witnessed the
+# transition in New York City, writing:
+#
+#   I heard the bells of St. Paul's strike on the old time.  Four
+#   minutes later, obedient to the electrical signal from the Naval
+#   Observatory ... the time-ball made its rapid descent, the chimes
+#   of old Trinity rang twelve measured strokes, and local time was
+#   abandoned, probably forever.
+#
+# Most of the US soon followed suit.  See:
+# Bartky IR. The adoption of standard time. Technol Cult 1989 Jan;30(1):25-56.
+# http://dx.doi.org/10.2307/3105430
 
 # From Paul Eggert (2005-04-16):
 # That 1883 transition occurred at 12:00 new time, not at 12:00 old time.