National 2025 State Legislative Districts and Block Assignment File

## RDH Creation Date
01/15/2026

## Sources
[National 2024 State Legislative Districts and Block Assignment File] (https://redistrictingdatahub.org/dataset/national-2024-state-legislative-districts-and-block-assignment-file/)

Official State Legislative Lower District block assignment files in MS sourced from state sources via RDH website. Official State Legislative Lower District district boundary files in MS sourced from RDH website. 

Official State Legislative Upper District block assignment files in MS sourced from state sources via RDH website. Official State Legislative Upper District district boundary files in MS sourced from RDH website. 

Please view the README for the above files for more information on sourcing. 

This file is intended to be joined to 2025 state legislative election results. Please be aware that there may have been elections to finish terms on old districts and that these districts may not always be the correct ones to use. For states that did not hold a state legislative election in 2025, the state legislative boundaries in effect during the year are used.

Additionally, some states use staggered elections for their legislative districts. Please be aware that some districts may have neither a representative currently representing that particular district nor an election on the new districts, depending on when the districts were passed and the state's particular rules.

## Fields
Field Name Description
***national_2025_elections_st_leg_boundaries_baf.csv***
GEOID20    2020 Census Block GEOID
SLDU       State Legislative Upper House District Name or Number
SLDL       State Legislative Lower House District Name or Number
FLOTERIAL  Floterial District Name or Number

***national_2025_elections_st_leg_lower_nh_floterial_boundaries***
DISTRICT   District Name or Number
STATE      State Abbreviation

***national_2025_elections_st_leg_lower_boundaries***
DISTRICT   District Name or Number
STATE      State Abbreviation

***national_2025_elections_st_leg_upper_boundaries***
DISTRICT   District Name or Number
STATE      State Abbreviation

## Processing Notes
This file was constructed by loading in the 2024 national file and swapping in the BAF and shapefile data from the "Post-Redistricting" file for the following states and levels.

For the state legislative lower district level: MS
For the state legislative upper district level: MS

Block assignment files in MS were constructed using the maup software package's assign function on official PL block boundaries. These assignments were checked against those of DRA and found to match exactly.

## Additional Notes
In the BAF, the "FLOTERIAL" field is not applicable and marked "NO FLOTERIAL" for all states except New Hampshire. In New Hampshire, the state legislative lower house has both base districts (represented by the 'SLDL' field) and floterials (represented by the "FLOTERIAL" field). Not all blocks in New Hampshire are nested within a floterial and those that are not are assigned "NO VALUE" in the "FLOTERIAL" field. The floterial districts are stored in a separate file to prevent unintentional overlaps in processing.

For states with one map for state legislative districts, the same values were used for the "SLDL" and "SLDU" fields. Nebraska is an exception to this, as it does not have a lower chamber in its state legislature, so for the "SLDL" field all blocks are assigned "NO SLDL". Some blocks may not have assignments for SLDU or SLDL districts. These blocks are given "NO VALUE" in their respective fields.

When creating the district shapefiles, "NO VALUE" and "NO SLDL" districts are filtered out.

Please email info@redistrictingdatahub.org for any questions about this dataset.