List some of the occupations open to women by the war

Manufacturing was the most surprising at the time . Rosie the Riveter was made famous as a lovely woman in coveralls helping build airplanes for the war effort .

In all wars, women have traditionally taken over the jobs available at the time; plus running their homes and raising their children alone. I need to know which war you are asking about. 

During World War I, women worked at manufacturing jobs and they farmed. Many of them joined the military and the Red Cross.Manufacturing was the most surprising at the time. Rosie the Riveter was made famous as a lovely woman in coveralls helping build airplanes for the war effort.
During WW1 a lot of women went to work in occupations that had previously been done by men. They worked in farming, forestry, on the railways and buses, as drivers etc. A lot of them worked in munitions factories. In the UK, women joined the newly formed women's auxilliary services, the Army, Navy and Airforce, but I understand America did not have official women's services until WW2. In the UK women also joined the newly formed women's Police Serivce (I understand women were admitted to the police force in the USA from 1910). 

Harriet Stanton Blatch wrote: 

'The American woman is going over the top. Four hundred and more are busy on aeroplanes at the Curtiss works. The manager of a munition shop where to-day but fifty women are employed, is putting up a dormitory to accomodate five hundred. An index of expectation! Five thousand are employed by the REmington Arms Company at Bridgeport. At the International Arms and Fuse Company at Bloomfiled, New Jersey, two thousand, eight hundred are employed. 

Nor are the railways neglecting to fill up gaps in their working force with women. The Pennsylvania road, it is said, has recruited some seven hundred of them. In the Erie Railroad women are not only engaged as 'work classifiers' in the locomotive clerical department, but hardy Polish women are employed in the car repair shops. They move great wheels as if possessed of the strength of Hercules. 

The professional woman is going over the top, and with a good opinion of herself. "I can do this work better than any man" was the announcement made by a young woman from the Pacific Coast as she descended upon the city hall in an eastern town, credentials in her hand, and asked for the position of city chemist. There was not a microbe she did not know to its undoing, or a deadly poison she could not bring from its hiding place. The town had suffered from graft and the mayor, thinking a woman might scare the thieves as well as the bacteria, appointed the chemist who believed in herself. And she is just one of many who have been taking up such work. 

Formerly two-thirds of the positions filled by the New York Inercollegiate Bureau of Occupations were secretarial or teaching positions, now three-fourths of its applicants have been placed as physicists, chemists, office managers, sanitary experts, exhibit secretaries, and the like. Of the women placed, four times as many as formerly get salaries ranging about eighteen hundred dollars a year.'Source(s):'The Virago book of women in the Great War' edited by Joyce Marlow

1920 census

the census was scheduled for january the 1st, as the government believed that more farmers would be in their homes by that time instead of april. the census did not ask about unemployment, the number of children, and how long was a couple married were not taken into consideration. individuals were considered as residents of the places they normally slept, not the places were they worked at or visited.

2010 census

the census was scheduled for april 1st, 2010. it was the shortest census in history: it only contained 10 questions related to name, age, gender, ethnicity, relationship, and whether the citizen owned a home or rented one. the government launched a website in order to provide the citizens with information regarding the census. there were also "teach census weeks" in schools nationwide.

The theory is land mass basically what they said.