I'm trying to find a report of federal early childhood education funding levels by state, by year. Any ideas?
ED.gov's State Fact Sheets on Proposed Federal Funding for Preschool for All is the report you are seeking. These reports are all about "Increasing Access to High-Quality Early Childhood Education", divided by state, and include federal funding data:
http://www2.ed.gov/about/inits/ed/earlylearning/increasing-access/index.html
Head Start Program datasets provide annual information on demographics, state allocations, program statistics, and general information on Head Start enrollment history:
http://eclkc.ohs.acf.hhs.gov/hslc/data/factsheets
Early Learning Initiative Awards
http://www2.ed.gov/programs/racetothetop-earlylearningchallenge/awards.html
Preschool Development and Expansion Grants and
http://www2.ed.gov/programs/preschooldevelopmentgrants/pdgfactsheet.pdf
Race to the Top–Early Learning Challenge (RTT-ELC) (since 2011) funding here:
http://www2.ed.gov/programs/racetothetop-earlylearningchallenge/2013-early-learning-challenge-flyer.pdf
CCD is an annual collection of fiscal and non-fiscal data about all public elementary and secondary schools, public school districts, and state education agencies throughout the United States.
http://datainventory.ed.gov/Search?seriesID=175
CCD home, more data
http://nces.ed.gov/ccd/
DOE's budget has a table comparing discretionary funding by state
http://www.nea.org/assets/docs/House-FY16-BR-Impact-on-ED-Discretionary-Title-I-and-IDEA_by_State.pdf
not what you asked for
this resource library has data, essentially comparing each state's performance (or lack thereof), as well as local government activities/spending and comparisons. Its actually really high quality data.
http://www2.ed.gov/about/offices/list/opepd/ppss/reports.html
Preschool Funding Trends by State Report:
http://www.nieer.org/publications/policy-reports/trends-state-funded-preschool-programs-survey-findings-2001-2002-2011
data:
http://www.nieer.org/sites/nieer/files/Trends%20in%20State%20Funded%20Preschool%20Programs_0.pdf
NIER publishes a Preschool Yearbook with state data comparisons:
http://nieer.org/yearbook