Investors looking for safe, long-term investments often start their search on the Dow Jones Industrial Average (^DJI -0.98%), a group of 30 of the best-known companies in the world. These businesses are behemoths in a diverse set of industries that have generated profits and cash flow for years.

When companies get that big, one of the ways they reward investors is paying them a dividend, and buying long-lasting dividend stocks is one of the best ways to beat the market. Right now, AT&T (T -1.37%) is the Dow's highest yielding dividend at 5.2%, and that high yield have been building over the past decade.

How to build a high dividend stock
AT&T's high dividend yield has been built over the past decade as the company has steadily increased its payout. Year after year, AT&T's dividend has increased, and since 2008 the stock is actually down slightly. The result is the high dividend yield we see today.

T Dividend Chart

T Dividend data by YCharts

Sometimes when yields rise that high, it's a sign that the business is headed for trouble and management is paying shareholders as much as they can while cash is still flowing. But for AT&T, the wireless business couldn't be stronger and it's in a perfect strategic position to grow in the market.

AT&T currently has something of a duopoly with Verizon Wireless at the top of the wireless landscape, a business that's still growing. That position is critical, because the billions of dollars spent to acquire spectrum and build its network can't easily be replicated by competitors, forcing them to compete solely on price.

In the meantime, AT&T's business continues to spit out billions of dollars of cash every year, some of which is also returned to investors in the form of a dividend.

Foolish bottom line
AT&T has everything investors should like in a dividend stock. Its core business has a solid competitive moat, margins and cash flow are consistent year after year, and the stagnant stock price has led to a strong yield for investors buying today.

This is the highest yielding stock on the Dow, and investors looking to beat the market should take a second look at how attractive AT&T is as an investment right now.