approximately, how many federal, state, and local law enforcement
agencies exist in the United States?
Can you give me a breakdown of each data segment?

Thanks for the assist,
Charles Markosi III
CEO/President
Impact Technologies of Lakewood Ranch, Inc.

Dear chasm38-ga

The latest official figures available are for 1996. These figures are
from U.S. Department of Justice, Bureau of Justice Statistics
http://www.ojp.usdoj.gov/bjs/lawenf.htm

"In 1996 there were about 738,000 full-time sworn law enforcement
officers in the United States
 
Type of agency   Number of agencies   Number of full-time sworn
officers

Total  738,028   
All State and local          18,769          663,535   
Local police                 13,578          410,956   
Sheriff                      3,088           152,922   
Primary State police            49           54,587   
Special police                1,316          43,082   
Texas constable                               1,988   
Federal*                                     74,493   
Note: Special police category includes both State-level and
local-level agencies. Five consolidated police-sheriffs are included
under local police category.
*Non-military federal officers authorized to carry firearms and make
arrests."

You will note this does not provide the number of Federal Agencies.
From http://www.ojp.usdoj.gov/bjs/fedle.htm we obtain the number of
officers involved in Federal Agencies but not the number of agencies.
However, counting the related sites at the bottom of the page, there
are 8.

Please do not hesitate to ask for clarification of this answer.

answerfinder-ga

Search strategy
us +statistics
://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=us+statistics

First rate job of researching. Thank you for freeing up my time to
accomplish more in the same amount of time.

Bravo,
Charles Markosi III
CEO/President
Impact Technologies of Lakewood Ranch, Inc.