Dates relating to gauge of Pacific railroad.
Here are some dates relating to the gauge of the Pacific railroad–which may have some relavance to discussion of the gauge of the SF&SJ and their locomotives:
24 January 1863 Lincoln adopted 5' as gauge of rr (Bee 24 January). According to Griswold, this decision was made in Washington on 20 January.
9 October 1863 report that Congress changed gauge to 4'8-1/2" (Union 9 October)–note this report was less that three weeks before the laying of first rail on CP (26 October 1863)–and it was more likely the anticipated laying of rail that prompted the report rather than any fresh news from Washington. In fact–again according to Griswold–the bill setting the gauge was signed by Lincoln on 13 March 1863.
It is entirely consistent with these dates that the first three SF&SJ engines were built five-foot gauge and not converted until being set up in San Francisco. "San Jose" was in service standard gauge by 24 June 1863.
There was a considerable delay between the invoice for CP's "Stanford" on 19 March 1863 and its sailing from New York on 16 May. It has been speculated that this time was occupied in converting it from five-foot to Pacific standard. Its erection in California was reported in progress on 20 October.