In 1916, the Mexican peso was on a silver standard but severely destabilized by the Revolution. The average exchange rate was roughly 2.02 MXN per USD (i.e., 1 USD ≈ 2.02 MXN). Therefore:
100,000 MXN ÷ 2.02 ≈ 49,505 USD.
However, rates fluctuated wildly (1913–1917); actual conversion depended on location, currency type (gold vs. silver vs. revolutionary issues), and black-market premiums. By 1918, the peso had collapsed further.