(FORTUNE Small Business) – The market and the state have always been allies and enemies. The industrial revolution made that paradox greater. At the turn of the 20th century, government trustbusters were becoming heroes. But as companies grew larger, the little guys' dance with Uncle Sam--their patron and nemesis--got more intricate. Here are a few landmark events. What hurt? What helped? Your call.

--Julie Sloane

The taxman cometh (1913) Congress creates a permanent income tax. And in 1916, estate taxes (abandoned after the Civil War) return to help finance World War I. The "death tax" pushes some families to sell their firms rather than pass them on. Later laws soften the blow for small business, but the topic lives on. Repeal could come in 2000.

Taking on the trusts (1914) Congress passes law named for its author, Democratic Sen. Henry De Lamar Clayton of Alabama. The Clayton Anti-Trust Act challenges monopolies, prohibits price fixing.

Main Street defense acts (1930-43) Both federal and state governments debate 390 (count 'em!) anti-chain-store bills. With such biggies as Dairy Queen and Piggly Wiggly multiplying like rabbits, legislators try to protect owners of smaller stores. A few laws pass, barring some pricing practices--mostly hollow victories. Americans may love Mom and Pop, but consumers always spend big at the bargain superstores.

The great divide (1933) The Glass-Steagall Act splits investment and commercial banking in a move to control corruption. But the law makes banks risk-averse, less creative in financing. Big customers get more breaks than small ones. After years of erosion, act is repealed in 2000.

Gold watches for everyone! (1935) New era of safety-net policies, hitched to the workplace. Social Security Act offers retirement security to every worker, creates a new link between employer and government. Companies' role as partners in social welfare will eventually involve them in such areas as health insurance, pensions, and antidiscrimination.

Bosses, can you spare a quarter? (1938) First national minimum wage is set at 25 cents an hour. A response to union power, and a boon for workers. Employers say nay; the market should set the price of labor. The minimum rises to $5.15 an hour by 2000, but it's still at the poverty line.

Pumping up the volume (1943) Businessman Wilson Harder sees small business voices in Washington get drowned out by big business. Starts the National Federation of Small Business. Since renamed, the National Federation of Independent Business (or NFIB) is the largest small business lobby group, with 600,000 members.

An agency of our own (1953) Congress creates the Small Business Administration (SBA) to champion and help fund small businesses.

You Inc. (1958) Tax-code changes create the Subchapter S corporation. The new status prevents profits from being taxed twice. Profit and loss will flow to the S corp. owner's individual tax statement.

'60s ascendant (1970) With voters listening to the voices of Rachel Carson (Silent Spring) and Ralph Nader, Congress creates the Occupational Health and Safety Administration (OSHA) and the Environmental Protection Agency (EPA). Businesses of all sizes go into resistance mode; small companies struggle most to handle changes and paperwork.

You've got mail (1972) The Defense Department's Arpanet, precursor to the Internet, begins using electronic mail. First "@" addresses mark the beginning of a gathering economic revolution.

Someone to watch over me (1976) SBA establishes the Office of Advocacy, giving it more of a voice on the Hill and in the Administration.

Big mess, big money (1980) The EPA organizes Superfund, a mandate that polluting businesses clean up the worst hazardous-waste sites. Lawsuits and loopholes (and movies like Erin Brockovich) still surfacing 20 years later. Does small business end up getting socked for nonhazardous waste? (See "Unintended Victims," July/August.)

The great deregulator (1981-86) Ronald Reagan slices at regulation and taxes. Some "burdens" are lifted, and movement spreads to states and towns. But federal deregulation of industries such as airlines leads to even bigger, more powerful competitors.

Global assist (1983) Congress recharters the Export-Import Bank. New goal: Help small business go global. Today, more than 16% of Exim's $13 billion budget in export financing goes to small firms.

Revival movement (1993) Washington designates 105 depressed urban and rural areas "empowerment zones." Tax credits and social services improvements targeted to attract business and investment. Six big cities, including Atlanta and Chicago, each get $100 million block grants.

Family values (1993) Congress orders companies with 50 or more employees to allow workers 12 weeks a year off for birth, adoption, or illness. Leaves are unpaid, but job is guaranteed.

Dental policy (1996) Congress gives the SBA more teeth. Under the Small Business Regulatory Enforcement and Fairness Act, the SBA's Office of Advocacy can force agencies such as EPA and OSHA to consider how their new rules will affect small businesses.

Netting a tax break (1998) Internet Tax Freedom Act bans Internet taxes until 2001. E-commerce cheers: Taxes would stifle its growth. Bricks-and-mortars scream: unfair advantage for dot-coms. The moratorium could be extended till 2006.

Innovations for innovators (1999) Major revisions overhaul the U.S. patent system, streamlining the process. Big change: Patent materials go public faster and are easier to challenge.

Back to the future (2000) After soap-opera-esque trial, court orders a breakup of Microsoft. The biggest antitrust case since Standard Oil. Will Bill Gates's customers and competitors win or lose? Stay tuned.