Starting in 1900 socialism in many forms started to take over the country, resulting in the great depression, the new deal, etc. But still, between 1900-2000 despite inflation eroding the purchasing power of the dollar by %90+, the standard of living for the lowest %20 of americans increased drastically. We went from nobody having any electric utilities in 1900 (of those in poverty, maybe lights and phone service) to it being fairly common for the lower %20 to have computers and internet and TVs and electric dishwashers, etc.
Too long of a time horizon? Look at india from 1980-2000. India is a socialist country and did not embrace pure capitalism, but had reforms that greatly reduced buracracy making starting small businesses much easier. The per-capita income of India doubled in that time period. That is over a billion people. Many of them are still poor, but their relations who are now living in first world standards can send money back home and the quality of life of the poor was improved dramatically-- just by lessening the burdends of socialism slightly.
Seriously, if you study economics, and you look at history, you'll find that where a country has a relatively free economy, the standard of living of the poorest %20 improves. Where a country has a relatively unfree economy, ranging from British socialism to German socialism to the USSR and North Korea, the poor have much lower standards of living.
If socialism is very dominant, it is true that there is "less poverty", but this is simply because everyone but the government is made to be poor. The only economic equality historically comes from everyone being poor.
--
Finally, I think that, given that the purpose of this site is to foster a startup spirit, you really should question whether a startup is for you if you reject capitalism.
I don't see how you can make good business deals, treat your employees right, or be a success if you thin the very nature of what you're doing is bad or evil.
Capitalism works because in a consentual exchange, both parties profit. When we trade, we are trading something we value relatively less for something we value relatively more. The apple farmer has so many apples, he'd rather have money, while the cobbler has no apples and wants to buy some.
When you give government control over the economy you naturally create centralized planning and inefficiencies that lead to shortages. Either they price things too high or too low, because they aren't aware of the market signals. Compulsion of force eliminates choice which eliminates the method by which consumers give feedback to economic entities. This is why there was scarcity in the USSR while there was abundance in the USA despite the USSR having more resources overall.
Of course, it is also in governments interest to indoctrinate people with the idea that they need government, which is why governments take over schools and then proceed to teach children that socialism is necessary to for "equity" while ignoring that it has failed everywhere (even the USA.)
Study economics. It isn't that difficult of a subject. The obfuscation and handwaving is all about trying to make keynsianism seem viable. Economics in one lesson, by henry hazlit is free online from various sites and gives very succinct arguments for why various programs do or don't work, and how the world works economically.
We're in a depression in the US caused by a distortion of the market from government. Under clinton it was decreed that loaning money only to people who could repay it was racist, and under Bush it was decreed that the rate of interest should be below the rate of inflation. This caused the housing bubble and the consequent bust. It is no wonder that the perpetrators of this crime -- years after it turned out that there was no racial bias in the loaning results-- blamed the wall street banks and "bailed them out", often forcing solvent banks like wells fargo to take "Bailouts" even though they didn't need them...and to try to push thru congress the power to arbitrarily force mergers of banks at the federal reserve level.
Capitalism works. Freedom works. Let people be and they will make better choices for themselves. Try to impose your whims on them and you will make their lives worse.
You need to embrace this if you want to run a business.