With football season upon us, I've become a little nostalgic about my home state of Maryland. No matter what you think of the Ravens, I've found that looking close to home for investment ideas can lead to discovering a diverse range of successful and growing businesses, in which you can invest more than your Sunday afternoon.

Economy in a good state
Maryland benefits from being close to the booming local economy in the nation's capital. Maryland is home to many of the defense and aerospace companies that are contracted by the federal government to support the military. Maryland is also a leader in the information technology space and the biotech field, with strength in human genome research and the applications that result from this work. Importantly in this slow economy, Maryland is one of only eight states in the country to retain a AAA bond rating in 2010. Let's look at some Maryland businesses that are revenue generators for the state and perhaps your portfolio as well.

Human Genome Sciences (Nasdaq: HGSI)
Human Genome Sciences is one of the big comeback stories of the past two years, as investors could have bought shares in this genome research leader at the March 2009 lows for less than $1. The stock is now pushing $30 as investors await more news on the company's highly anticipated lupus drug. The autoimmune deficiency disease has not seen any new treatments come to market in the past 50 years, so HGSI's Benlysta represents a potentially significant breakthrough. The company has partnered with GlaxoSmithKline (NYSE: GSK) to bring the drug to market in the U.S. and Europe.

The FDA has given the drug priority review status with a target of giving HGSI and GlaxoSmithKline a response by the end of this year. Analyst estimates have sales in the $2 billion to $3 billion range by 2016, and are touting the drug as a breakthrough against this disease.

Under Armour (NYSE: UA)
This Baltimore-based company is also one of Maryland's most well-known, thanks to its in-your-face branding and product placement on some of the best athletes in the world. The sports apparel company recently handily beat earnings estimates in the second quarter, but the reasons go beyond growth in sales at the company's significant retail partners, including Dick's Sporting Goods (NYSE: DKS) and Cabela's (NYSE: CAB). While these sales have been strong, the company has been extremely successful in growing its direct-to-consumer outlet store business. The company was able to grow year-over-year sales by more than 60% in this higher margin business.

Under Armour has struggled with its athletic footwear line as sales were down 4.5% year over year in the most recent quarter. In order to keep impressing investors, the company will need to find a way to increase sales in this line. It won't be easy stealing share from the industry's shoe giant, Nike (NYSE: NKE).

T. Rowe Price (Nasdaq: TROW)
The Baltimore-based asset manager has built a very strong reputation not only locally but globally as well. T. Rowe's reputation has been enhanced by the company's commitment to annual dividend increases, which have been consistent since its IPO in 1986. Further, as a money manager, T. Rowe has trumped its competitors in the success of its mutual fund business. More than 68% of the firm's mutual fund assets are invested in four- or five-star-rated funds, well above the industry average of 40%.

While T. Rowe has remained successful in an extremely competitive business, the entire mutual fund industry is under siege from the proliferation of exchange-traded funds. These tools provide a similar product at much lower management cost in most cases. In order to continue its successful growth, T. Rowe must continue to add value for its clients as a manager and advisor.

Staying close to home
No matter where they are, looking at companies that play an important role in the growth and prosperity of your community is a good way to find new investment ideas. In Maryland, the Ravens aren't the only winners in town, and I'm definitely not talking about the Orioles.

How does your state's economy stack up against Maryland? Can anyone stop Ray Lewis and the Ravens? Let me have it in the comment box below.

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Andrew Bond owns no shares in the companies listed. GlaxoSmithKline is a Motley Fool Global Gains selection. Nike is a Motley Fool Stock Advisor selection. Under Armour is a Motley Fool Rule Breakers pick and a Motley Fool Hidden Gems recommendation. The Fool owns shares of Under Armour and GlaxoSmithKline. Try any of our Foolish newsletters today, free for 30 days. The Fool has a disclosure policy.