My somewhat final list of key fields at the county level, top level (race, age, Foreign, not race by age by foreign). With a fair amount of time ( 3-4 weekends under by belt ), this is what I've found to be most interesting at the county level. In case anyone finds this helpful.

Column Name | Label | My_Name |

S0101_C01_001E | Estimate!!Total!!Total population | Tot_Pop |

S0101_C01_030E | Estimate!!Total!!Total population!!SELECTED AGE CATEGORIES!!65 years and over | Pop_65+ |

S0101_C01_032E | Estimate!!Total!!Total population!!SUMMARY INDICATORS!!Median age (years) | Pop_MedianA |

S0101_C02_002E | Estimate!!Percent!!Total population!!AGE!!Under 5 years | Pop_<5 |

S0101_C02_022E | Estimate!!Percent!!Total population!!SELECTED AGE CATEGORIES!!Under 18 years | Pop_<18 |

S0101_C02_026E | Estimate!!Percent!!Total population!!SELECTED AGE CATEGORIES!!18 years and over | Pop_18+ |

S0101_C05_001E | Estimate!!Female!!Total population | Female% |

S1101_C01_002E | Estimate!!Total!!HOUSEHOLDS!!Average household size | H_Size |

S1101_C01_004E | Estimate!!Total!!FAMILIES!!Average family size | F_Size |

S1101_C01_019E | Estimate!!Total!!Total households!!HOUSING TENURE!!Renter-occupied housing units | Rent% |

S1501_C02_005E | Estimate!!Percent!!AGE BY EDUCATIONAL ATTAINMENT!!Population 18 to 24 years!!Bachelor's degree or higher | 18-24BA+ |

S1501_C02_015E | Estimate!!Percent!!AGE BY EDUCATIONAL ATTAINMENT!!Population 25 years and over!!Bachelor's degree or higher | 25+BA+ |

S1701_C03_001E | Estimate!!Percent below poverty level!!Population for whom poverty status is determined | Poverty |

S1701_C03_002E | Estimate!!Percent below poverty level!!Population for whom poverty status is determined!!AGE!!Under 18 years | Pov_<18 |

S1701_C03_003E | Estimate!!Percent below poverty level!!Population for whom poverty status is determined!!AGE!!Under 18 years!!Under 5 years | Pov_<5 |

S1701_C03_010E | Estimate!!Percent below poverty level!!Population for whom poverty status is determined!!AGE!!65 years and over | Pov_65+ |

S1901_C01_002E | Estimate!!Households!!Total!!Less than $10,000 | H_<$10k |

S1901_C01_011E | Estimate!!Households!!Total!!$200,000 or more | H_>$200k |

S1901_C01_013E | Estimate!!Households!!Mean income (dollars) | H_$Mean_I |

S2101_C04_001E | Estimate!!Percent Veterans!!Civilian population 18 years and over | VA |

S2201_C04_001E | Estimate!!Percent households receiving food stamps/SNAP!!Households | Food_SNAP% |

S2301_C02_001E | Estimate!!Labor Force Participation Rate!!Population 16 years and over | Labor% |

S2301_C04_001E | Estimate!!Unemployment rate!!Population 16 years and over | UI% |

S2303_C01_031E | Estimate!!Total!!Population 16 to 64 years!!Mean usual hours worked for workers | Mean_Hrs |

S2401_C01_018E | Estimate!!Total!!Civilian employed population 16 years and over!!Service occupations: | Ser_Work% |

S2701_C01_017E | Estimate!!Total!!Civilian noninstitutionalized population!!RACE AND HISPANIC OR LATINO ORIGIN!!Black or African American alone | Black% |

S2701_C01_023E | Estimate!!Total!!Civilian noninstitutionalized population!!RACE AND HISPANIC OR LATINO ORIGIN!!Hispanic or Latino (of any race) | Hispanic% |

S2701_C01_024E | Estimate!!Total!!Civilian noninstitutionalized population!!RACE AND HISPANIC OR LATINO ORIGIN!!White alone, not Hispanic or Latino | White% |

S2701_C01_032E | Estimate!!Total!!Civilian noninstitutionalized population!!NATIVITY AND U.S. CITIZENSHIP STATUS!!Foreign born | Foreign% |

S2701_C01_035E | Estimate!!Total!!Civilian noninstitutionalized population!!DISABILITY STATUS!!With a disability | Disability% |

S2701_C05_001E | Estimate!!Percent Uninsured!!Civilian noninstitutionalized population | NoInsureAll% |

S2701_C05_002E | Estimate!!Percent Uninsured!!Civilian noninstitutionalized population!!AGE!!Under 6 years | NoInsure<6% |

S2701_C05_011E | Estimate!!Percent Uninsured!!Civilian noninstitutionalized population!!AGE!!Under 19 years | NoInsur<19% |

B09010_001E | Estimate!!Total: | Tot_<18H |

B09010_002E | Estimate!!Total:!!Living in household with Supplemental Security Income (SSI), cash public assistance income, or Food Stamps/SNAP in the past 12 months: | SNAP$SSI_<18% |

B19055_001E | Estimate!!Total: | Tot_H |

B19055_002E | Estimate!!Total:!!With Social Security income | SS_I |

B19056_002E | Estimate!!Total:!!With Supplemental Security Income (SSI) | Sup_SS_I |

B19057_002E | Estimate!!Total:!!With public assistance income | Cash_Asst |

B19058_002E | Estimate!!Total:!!With cash public assistance or Food Stamps/SNAP | Cash_SNAP |

B19065_001E | Estimate!!Aggregate Social Security income in the past 12 months (in 2021 inflation-adjusted dollars) | SS_Tot$ |

B19083_001E | Estimate!!Gini Index | Gini_Index |

B25031_001E | Estimate!!Median gross rent --!!Total: | Median_gRent |

B25058_001E | Estimate!!Median contract rent | Median_cRent |

B25070_001E | Estimate!!Total: | G_Rent |

B25070_010E | Estimate!!Total:!!50.0 percent or more | G_Rent_50%I |

B25071_001E | Estimate!!Median gross rent as a percentage of household income | G_Rent_%I |

B25105_001E | Estimate!!Median monthly housing costs | Median_H$ |

B99087_001E | Estimate!!Total: | Tot_H |

B99087_005E | Estimate!!Total:!!Worked from home | Work_Home |