Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_1900 ( "Township" text, "County" text, "Pop. (2010)" real, "Land ( sqmi )" text, "Water (sqmi)" text, "Latitude" text, "Longitude" text, "GEO ID" real, "ANSI code" real )

### Question ###
Name the least ansi code for 609 population 2010

### Accurate SQL ###

SELECT MIN("ANSI code") FROM table_1900 WHERE "Pop. (2010)" = '609'