Tens of thousands of people are expected to join nationwide protests across the US over the Trump administration's strict migrant policy.
More than 630 events are planned calling for migrant families split up at the US border to be reunited.
Some 2,000 children remain separated from their parents, despite President Donald Trump's executive order ending the controversial policy.
He bowed to public pressure after weeks of domestic and international outrage, reports reuters.
The order stopped children being taken from parents who face criminal prosecution as part of the president's policy of "zero tolerance" towards illegal crossings of the US border from Mexico.
Faced with a backlash, President Trump instead promised to "keep families together" in migrant detention centres.
However, critics say the order did not address the issue of families already separated, with 2,342 children taken away from their parents between 5 May and 9 June alone.
Earlier this week, a judge in California ordered the families to be reunited within 30 days.
It is likely to be one of the biggest protests over immigration, an issue that has proved deeply divisive under the presidency of Donald Trump.