IND1950 to Agriculture, Manufacturing, and Service Sector?

I am trying to classify the IND1950 variable to their corresponding sector - Agriculture, Manufacturing, and Services. I am using census data for years from 1940 to 2000 and 5 years ACS for 2010. I wanted to know how can I map the IND1950 variable to the three sectors correctly. Any reference for paper which has made this classification consistently would also be helpful.

I’m not aware of any crosswalks that map IND1950 into these three sectors. The US Census Bureau currently uses the 2017 North American Industry Classification System (NAICS) to classify industries into one of 20 sectors, 10 supersectors, and two super sector groups (the goods-producing industries and service-providing industries); you can find older classification systems used by Census on this crosswalks page. You may be able to create your own crosswalk between IND1950 and the NAICS groupings (available in the variable INDNAICS). However, since the NAICS is regularly updated, you would need to decide on a vintage of the NACIS to use to compare how IND1950 maps into these categories (see this blogpost on how to construct your own industry crosswalk). As an alternative, coding for IND1950 does provide a consistent grouping of industries into 16 sectors, including agriculture, forestry, and fishing, manufacturing of durable goods, manufacturing of nondurable goods, and several different service sectors. You might use these to construct your own grouping of industries into your sectors of interest.

Thanks for the answer. Does there exists crosswalk to map ind1950 to ind1990?

While IPUMS does not publish a separate crosswalk from IND1950 to IND1990, you can obtain a crosswalk by adding both variables to your extract and observing which IND1950 industries match to which IND1990 industries. By assigning any individual to a sector based on IND1990, you will immediately know the IND1950 code because both are assigned to the same individual.