"Will the march become a movement"? 
I do so hope.
A recent NCR article asked about prophets for today. Prophets are usually portrayed as individuals who stand out - dishonoured in their own country.  They  persist despite flaws and limitations, and declare in urgency, inspired by the need, to engage, inspire, even create, community. 
An essential element - they are somehow "signed", mandated, where others with similar message might go unnoticed. The Spirit?
The sign? "E Pluribus Unum". 
The timing of the "sister's march" its sequence with the Inauguration of a President who contemptuously identifies his "ego" as the "one" of the Great Seal declaration: "E Pluribus Unum", dishonouring its foundation and those in whom it was and is grounded.
Today's prophet and prophesy may, be that community of women- "E Pluribus Unum" of the women standing, joined by men, in solidarity FOR the very values dishonoured - dignity, respect, inclusion, equality- a "one" from the many. At home and globally.