Question: What date did the Smithsonian food workers protest?
About the article "National Air and Space Museum", section "Controversies".

Candidate passages:
 "Brother John Sellers" (Vanguard Records, 1954) "Sings Blues and Folk Songs" (Vanguard, 1954) "Baptist Shouts and Gospel Songs" (Monitor Records/Smithsonian Folkways) "Big Boat Up The River" (Monitor Records/Smithsonian Folkways) "Classic Protest Songs from Smithsonian Folkways" (Smithsonian Folkways) "Let Praise Arise" (Integrity Music, 1984)  
Violent clashes broke out in Mahalla on November 27, 2012 over the constitution proposed by the Muslim Brotherhood; some Misr Helwan workers participating in the protest stated that they did not participate in an attack on the Muslim Brotherhood's Freedom and Justice Party headquarters.
On December 7 protesters in El-Mahalla El-Kubra stormed the city hall and declared independence from the "Muslim Brotherhood State."
One Misr Helwan worker, arrested on previous occasions by the Mubarak government, explained workers' attitudes to the Muslim brotherhood:The revolution's slogan was "Justice, bread and freedom," but we've obtained none of these.
The government just increased the price of electricity by 15% while our wages have stagnated.
They're now trying to impose a discriminatory constitution, written for and by Islamists.
The Muslim Brotherhood doesn't represent me... they take with one hand what they pretend to give with the other.
They're even worse than Mubarak.
"Other protestors noted that Misr Helwan workers could launch a general strike, slowing or crippling the national economy.
One worker speaking to "Al-Ahram" criticized the constitution, stating that article 14 tied wages to production and not food prices.
Voting in Mahalla was largely peaceful on the day of the election. 
  Mike Cohen (1972)  What Did You Expect?
(1973) Discographic details from Smithsonian Institution  Some of Us Had To Live (1976) Discographic details from Smithsonian Institution  
American shops from Oklahoma (called Okies) were often hostile toward Mexicans because they felt they were taking away their jobs.
Mexican migrant laborers would work for much lower pay, so employers would much rather hire them.
There was also much tension between the migrant workers on the fields.
Some felt that their conditions were unlivable, and they deserved much better, so they began to protest and fight for what they believed.
Still, others refused to join the protest in fear that they would be fired.
In the 1920s and 1930s (about the time story takes place) California remained about 88% white.
Most of these people were those who owned the land, while the 36,800 workers, many of whom were Mexicans, did not. 
In the 19th century, Chinese in San Francisco operated sophisticated and sometimes luxurious restaurants patronized mainly by Chinese, while restaurants in smaller towns served what their customers requested, ranging from pork chop sandwiches and apple pie to beans and eggs.
These smaller restaurants developed American Chinese cuisine when they modified their food to suit a more American palate.
First catering to miners and railroad workers, they established new eateries in towns where Chinese food was completely unknown, adapting local ingredients and catering to their customers' tastes.
In the process, cooks adapted southern Chinese dishes such as chop suey, and developed a style of Chinese food not found in China.
Restaurants (along with Chinese laundries) provided an ethnic niche for small businesses at a time when the Chinese people were excluded from most jobs in the wage economy by ethnic discrimination or lack of language fluency.
In 2011, the Smithsonian National Museum of American History displayed some of the historical background and cultural artifacts of American Chinese cuisine in its exhibit "Sweet & Sour: A Look at the History of Chinese Food in the United States".